Circuits for supplying isolated direct current (dc) voltage to surgical instruments

ABSTRACT

Provided is an apparatus, system, and method for managing radio frequency (RF) and ultrasonic signals output by a generator that includes a surgical instrument comprising an RF energy output and an ultrasonic energy output and a circuit configured to receive a combined RF and ultrasonic signal from the generator. The circuit may be configured to isolate a direct current (DC) voltage from the combined RF and ultrasonic signal. The DC voltage may then be used to power various electrical components of the surgical instrument while still providing RF energy and ultrasonic energy for surgical application.

PRIORITY

This application claims the benefit of U.S. Provisional Application Ser.No. 62/235,260, titled GENERATOR FOR PROVIDING COMBINED RADIO FREQUENCYAND ULTRASONIC ENERGIES, filed Sep. 30, 2015, U.S. ProvisionalApplication Ser. No. 62/235,368, titled CIRCUIT TOPOLOGIES FORGENERATOR, filed Sep. 30, 2015, and U.S. Provisional Application Ser.No. 62/235,466, titled SURGICAL INSTRUMENT WITH USER ADAPTABLEALGORITHMS, filed Sep. 30, 2015, the contents of each of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure generally relates to ultrasonic surgical systems,electrosurgical systems, and combination electrosurgical/ultrasonicsystems for performing surgical procedures such as coagulating, sealing,and/or cutting tissue. In particular, the present disclosure relates tocircuits for supplying isolated direct current (DC) voltage to surgicalinstruments.

BACKGROUND

Ultrasonic surgical instruments are finding increasingly widespreadapplications in surgical procedures by virtue of the unique performancecharacteristics of such instruments. Depending upon specific instrumentconfigurations and operational parameters, ultrasonic surgicalinstruments can provide substantially simultaneous cutting of tissue andhemostasis by coagulation, desirably minimizing patient trauma. Thecutting action is typically realized by an-end effector, or blade tip,at the distal end of the instrument, which transmits ultrasonic energyto tissue brought into contact with the end effector. Ultrasonicinstruments of this nature can be configured for open surgical use,laparoscopic, or endoscopic surgical procedures includingrobotic-assisted procedures.

Some surgical instruments utilize ultrasonic energy for both precisecutting and controlled coagulation. Ultrasonic energy cuts andcoagulates by vibrating a blade in contact with tissue. Vibrating athigh frequencies (e.g., 55,500 times per second), the ultrasonic bladedenatures protein in the tissue to form a sticky coagulum. Pressureexerted on tissue with the blade surface collapses blood vessels andallows the coagulum to form a hemostatic seal. The precision of cuttingand coagulation is controlled by the surgeon's technique and adjustingthe power level, blade edge, tissue traction, and blade pressure.

Electrosurgical devices for applying electrical energy to tissue inorder to treat and/or destroy the tissue are also finding increasinglywidespread applications in surgical procedures. An electrosurgicaldevice typically includes a hand piece, an instrument having adistally-mounted end effector (e.g., one or more electrodes). The endeffector can be positioned against the tissue such that electricalcurrent is introduced into the tissue. Electrosurgical devices can beconfigured for bipolar or monopolar operation. During bipolar operation,current is introduced into and returned from the tissue by active andreturn electrodes, respectively, of the end effector. During monopolaroperation, current is introduced into the tissue by an active electrodeof the end effector and returned through a return electrode (e.g., agrounding pad) separately located on a patient's body. Heat generated bythe current flowing through the tissue may form hemostatic seals withinthe tissue and/or between tissues and thus may be particularly usefulfor sealing blood vessels, for example. The end effector of anelectrosurgical device may also include a cutting member that is movablerelative to the tissue and the electrodes to transect the tissue.

Electrical energy applied by an electrosurgical device can betransmitted to the instrument by a generator in communication with thehand piece. The electrical energy may be in the form of radio frequency(“RF”) energy. RF energy is a form of electrical energy that may be inthe frequency range of 200 kilohertz (kHz) to 1 megahertz (MHz). Inapplication, an electrosurgical device can transmit low frequency RFenergy through tissue, which causes ionic agitation, or friction, ineffect resistive heating, thereby increasing the temperature of thetissue. Because a sharp boundary is created between the affected tissueand the surrounding tissue, surgeons can operate with a high level ofprecision and control, without sacrificing un-targeted adjacent tissue.The low operating temperatures of RF energy is useful for removing,shrinking, or sculpting soft tissue while simultaneously sealing bloodvessels. RF energy works particularly well on connective tissue, whichis primarily comprised of collagen and shrinks when contacted by heat.

A challenge of using these medical devices is the inability to fullycontrol and customize the functions of the surgical instruments. Itwould be desirable to provide a surgical instrument that overcomes someof the deficiencies of current instruments.

While several medical devices have been made and used, it is believedthat no one prior to the inventors has made or used the subject matterdescribed in the appended claims.

SUMMARY

In one aspect, the present disclosure is directed to a mixed energysurgical instrument that utilizes both ultrasonic and RF energymodalities. Multiple circuit topologies are disclosed which when one (ormore) of these circuit topologies are included in a mixed energysurgical instrument, the circuit topology enables a generator to driveboth RF and ultrasonic energy into tissue either simultaneously or byswitching between RF and ultrasonic.

In another aspect, the present disclosure is directed to a circuitconfiguration to provide isolated DC voltage to surgical instruments.According to various aspects, the circuit configuration is designed torectify RF and/or ultrasonic outputs supplied from a generator to asurgical instrument to charge an energy storage device. In one aspect,charging is accomplished while not driving therapeutic energy for thesurgical instrument. Such circuit topology will enable supplying DCvoltage to achieve multiple functionalities, for example, including:drive a DC (or stepper) motor; drive LED/s for illumination; and drive asensor which requires DC as supply, such as a strain-gauge.

In addition to the foregoing, various other method and/or system and/orprogram product aspects are set forth and described in the teachingssuch as text (e.g., claims and/or detailed description) and/or drawingsof the present disclosure.

The foregoing is a summary and thus may contain simplifications,generalizations, inclusions, and/or omissions of detail; consequently,those skilled in the art will appreciate that the summary isillustrative only and is NOT intended to be in any way limiting. Otheraspects, features, and advantages of the devices and/or processes and/orother subject matter described herein will become apparent in theteachings set forth herein.

In one or more various aspects, related systems include but are notlimited to circuitry and/or programming for effecting herein-referencedmethod aspects; the circuitry and/or programming can be virtually anycombination of hardware, software, and/or firmware configured to affectthe herein-referenced method aspects depending upon the design choicesof the system designer. In addition to the foregoing, various othermethod and/or system aspects are set forth and described in theteachings such as text (e.g., claims and/or detailed description) and/ordrawings of the present disclosure.

Further, it is understood that any one or more of thefollowing-described forms, expressions of forms, examples, can becombined with any one or more of the other following-described forms,expressions of forms, and examples.

Various forms are directed to improved ultrasonic surgical instrumentsconfigured for effecting tissue dissecting, cutting, and/or coagulationduring surgical procedures. In one form, an ultrasonic surgicalinstrument apparatus is configured for use in open surgical procedures,but has applications in other types of surgery, such as laparoscopic,endoscopic, and robotic-assisted procedures. Versatile use isfacilitated by selective use of ultrasonic energy.

The various forms will be described in combination with an ultrasonicinstrument as described herein. Such description is provided by way ofexample, and not limitation, and is not intended to limit the scope andapplications thereof. For example, any one of the described forms isuseful in combination with a multitude of ultrasonic instrumentsincluding those described in, for example, U.S. Pat. Nos. 5,938,633;5,935,144; 5,944,737; 5,322,055; 5,630,420; and 5,449,370, each of whichis herein incorporated by reference.

As will become apparent from the following description, it iscontemplated that forms of the surgical instrument described herein maybe used in association with an oscillator unit of a surgical system,whereby ultrasonic energy from the oscillator unit provides the desiredultrasonic actuation for the present surgical instrument. It is alsocontemplated that forms of the surgical instrument described herein maybe used in association with a signal generator unit of a surgicalsystem, whereby electrical energy in the form of radio frequencies (RF),for example, is used to provide feedback to the user regarding thesurgical instrument. The ultrasonic oscillator and/or the signalgenerator unit may be non-detachably integrated with the surgicalinstrument or may be provided as separate components, which can beelectrically attachable to the surgical instrument.

One form of the present surgical apparatus is particularly configuredfor disposable use by virtue of its straightforward construction.However, it is also contemplated that other forms of the presentsurgical instrument can be configured for non-disposable or multipleuses. Detachable connection of the present surgical instrument with anassociated oscillator and signal generator unit is presently disclosedfor single-patient use for illustrative purposes only. However,non-detachable integrated connection of the present surgical instrumentwith an associated oscillator and/or signal generator unit is alsocontemplated. Accordingly, various forms of the presently describedsurgical instruments may be configured for single use and/or multipleuses with either detachable and/or non-detachable integral oscillatorand/or signal generator unit, without limitation, and all combinationsof such configurations are contemplated to be within the scope of thepresent disclosure.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects and featuresdescribed above, further aspects and features will become apparent byreference to the drawings and the following detailed description.

FIGURES

The novel features described herein are set forth with particularity inthe appended claims. The various aspects, however, both as toorganization and methods of operation may be better understood byreference to the following description, taken in conjunction with theaccompanying drawings as follows:

FIG. 1 illustrates one form of a surgical system comprising a generatorand various surgical instruments usable therewith;

FIG. 2 is a diagram of the combination electrosurgical and ultrasonicinstrument shown in FIG. 1;

FIG. 3 is a diagram of the surgical system shown in FIG. 1;

FIG. 4 is a model illustrating motional branch current in one form;

FIG. 5 is a structural view of a generator architecture in one form;

FIG. 6 illustrates one form of a drive system of a generator, whichcreates the ultrasonic electrical signal for driving an ultrasonictransducer;

FIG. 7 illustrates one form of a drive system of a generator comprisinga tissue impedance module;

FIG. 8 illustrates an example of a combined radio frequency andultrasonic energy generator for delivering energy to a surgicalinstrument;

FIG. 9 is a diagram of a system for delivering combined radio frequencyand ultrasonic energy to a plurality of surgical instruments;

FIG. 10 illustrates a communications architecture of a system fordelivering combined radio frequency and ultrasonic energy to a pluralityof surgical instruments;

FIG. 11 illustrates a communications architecture of a system fordelivering combined radio frequency and ultrasonic energy to a pluralityof surgical instruments;

FIG. 12 illustrates a communications architecture of a system fordelivering combined radio frequency and ultrasonic energy to a pluralityof surgical instruments;

FIG. 13 is a circuit schematic for a system that is configured to manageRF and ultrasonic currents output by a generator according to one aspectof the present disclosure;

FIG. 14 displays graphs of simulation results of the circuit schematicshown in FIG. 13;

FIG. 15 displays graphs of simulation results of the circuit schematicshown in FIG. 13;

FIG. 16 displays graphs of simulation results of the circuit schematicshown in FIG. 13;

FIG. 17 displays graphs of simulation results of the circuit schematicshown in FIG. 13;

FIG. 18 displays graphs of simulation results of the circuit schematicshown in FIG. 13;

FIG. 19 displays graphs of simulation results of the circuit schematicshown in FIG. 13;

FIG. 20 is an illustration of a system configuration for a circuittopology configured to manage RF and ultrasonic currents output by agenerator according to one aspect of the present disclosure;

FIG. 21 is an example graph of two waveforms of energy from a generator;

FIG. 22 is an example graph of the sum of the waveforms of FIG. 21;

FIG. 23 is an example graph of sum of the waveforms of FIG. 21 with theRF waveform dependent on the ultrasonic waveform;

FIG. 24 is an example graph of the sum of the waveforms of FIG. 21 withthe RF waveform being a function of the ultrasonic waveform; and

FIG. 25 is an example graph of a complex RF waveform with a high crestfactor.

DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols and reference characters typically identify similarcomponents throughout the several views, unless context dictatesotherwise. The illustrative aspects described in the detaileddescription, drawings, and claims are not meant to be limiting. Otheraspects may be utilized, and other changes may be made, withoutdeparting from the spirit or scope of the subject matter presented here.

Before explaining the various aspects of the present disclosure indetail, it should be noted that the various aspects disclosed herein arenot limited in their application or use to the details of constructionand arrangement of parts illustrated in the accompanying drawings anddescription. Rather, the disclosed aspects may be positioned orincorporated in other aspects, variations and modifications thereof, andmay be practiced or carried out in various ways. Accordingly, aspectsdisclosed herein are illustrative in nature and are not meant to limitthe scope or application thereof. Furthermore, unless otherwiseindicated, the terms and expressions employed herein have been chosenfor the purpose of describing the aspects for the convenience of thereader and are not to limit the scope thereof. In addition, it should beunderstood that any one or more of the disclosed aspects, expressions ofaspects, and/or examples thereof, can be combined with any one or moreof the other disclosed aspects, expressions of aspects, and/or examplesthereof, without limitation.

Also, in the following description, it is to be understood that termssuch as front, back, inside, outside, top, bottom and the like are wordsof convenience and are not to be construed as limiting terms.Terminology used herein is not meant to be limiting insofar as devicesdescribed herein, or portions thereof, may be attached or utilized inother orientations. The various aspects will be described in more detailwith reference to the drawings.

This application is related to the following commonly owned patentapplications filed contemporaneously herewith:

Attorney Docket No. END7768USNP1/150449-1, titled CIRCUIT TOPOLOGIES FORCOMBINED GENERATOR, by Wiener et al.;Attorney Docket No. END7768USNP3/150449-3, titled FREQUENCY AGILEGENERATOR FOR A SURGICAL INSTRUMENT, by Yates et al.;Attorney Docket No. END7768USNP4/150449-4, titled, METHOD AND APPARATUSFOR SELECTING OPERATIONS OF A SURGICAL INSTRUMENT BASED ON USERINTENTION, by Asher et al.;Attorney Docket No. END7769USNP1/150448-1, titled GENERATOR FORDIGITALLY GENERATING ELECTRICAL SIGNAL WAVEFORMS FOR ELECTROSURGICAL ANDULTRASONIC SURGICAL INSTRUMENTS, by Wiener et al.;Attorney Docket No. END7769USNP2/150448-2, titled GENERATOR FORDIGITALLY GENERATING COMBINED ELECTRICAL SIGNAL WAVEFORMS FOR ULTRASONICSURGICAL INSTRUMENTS, by Wiener et al.;Attorney Docket No. END7769USNP3/150448-3, titled PROTECTION TECHNIQUESFOR GENERATOR FOR DIGITALLY GENERATING ELECTROSURGICAL AND ULTRASONICDIGITAL ELECTRICAL SIGNAL WAVEFORMS, by Yates et al.;each of which is incorporated herein by reference in its entirety.

This application also is related to the following commonly owned patentapplications filed on Jun. 9, 2016:

U.S. patent application Ser. No. 15/177,430, titled SURGICAL INSTRUMENTWITH USER ADAPTABLE TECHNIQUES;U.S. patent application Ser. No. 15/177,439, titled SURGICAL INSTRUMENTWITH USER ADAPTABLE TECHNIQUES BASED ON TISSUE TYPE;U.S. patent application Ser. No. 15/177,449, titled SURGICAL SYSTEM WITHUSER ADAPTABLE TECHNIQUES EMPLOYING MULTIPLE ENERGY MODALITIES BASED ONTISSUE;U.S. patent application Ser. No. 15/177,456, titled SURGICAL SYSTEM WITHUSER ADAPTABLE TECHNIQUES BASED ON TISSUE IMPEDANCE;U.S. patent application Ser. No. 15/177,466, titled SURGICAL SYSTEM WITHUSER ADAPTABLE TECHNIQUES EMPLOYING SIMULTANEOUS ENERGY MODALITIES BASEDON TISSUE PARAMETERS;each of which is incorporated herein by reference in its entirety.

With reference to FIGS. 1-5, one form of a surgical system 10 includinga surgical instrument is illustrated. FIG. 1 illustrates one form of asurgical system 10 comprising a generator 100 and various surgicalinstruments 104, 106, 108 usable therewith, where the surgicalinstrument 104 is an ultrasonic surgical instrument, the surgicalinstrument 106 is an RF electrosurgical instrument 106, and themultifunction surgical instrument 108 is a combination ultrasonic/RFelectrosurgical instrument. FIG. 2 is a diagram of the multifunctionsurgical instrument 108 shown in FIG. 1. With reference to both FIGS. 1and 2, the generator 100 is configurable for use with a variety ofsurgical instruments.

According to various forms, the generator 100 may be configurable foruse with different surgical instruments of different types including,for example, ultrasonic surgical instruments 104, RF electrosurgicalinstruments 106, and multifunction surgical instruments 108 thatintegrate RF and ultrasonic energies delivered simultaneously from thegenerator 100. Although in the form of FIG. 1, the generator 100 isshown separate from the surgical instruments 104, 106, 108 in one form,the generator 100 may be formed integrally with any of the surgicalinstruments 104, 106, 108 to form a unitary surgical system. Thegenerator 100 comprises an input device 110 located on a front panel ofthe generator 100 console. The input device 110 may comprise anysuitable device that generates signals suitable for programming theoperation of the generator 100.

FIG. 1 illustrates a generator 100 configured to drive multiple surgicalinstruments 104, 106, 108. The first surgical instrument 104 is anultrasonic surgical instrument 104 and comprises a handpiece 105 (HP),an ultrasonic transducer 120, a shaft 126, and an end effector 122. Theend effector 122 comprises an ultrasonic blade 128 acoustically coupledto the ultrasonic transducer 120 and a clamp arm 140. The handpiece 105comprises a trigger 143 to operate the clamp arm 140 and a combinationof the toggle buttons 134 a, 134 b, 134 c to energize and drive theultrasonic blade 128 or other function. The toggle buttons 134 a, 134 b,134 c can be configured to energize the ultrasonic transducer 120 withthe generator 100.

Still with reference to FIG. 1, the generator 100 also is configured todrive a second surgical instrument 106. The second surgical instrument106 is an RF electrosurgical instrument and comprises a handpiece 107(HP), a shaft 127, and an end effector 124. The end effector 124comprises electrodes in the clamp arms 142 a, 142 b and return throughan electrical conductor portion of the shaft 127. The electrodes arecoupled to and energized by a bipolar energy source within the generator100. The handpiece 107 comprises a trigger 145 to operate the clamp arms142 a, 142 b and an energy button 135 to actuate an energy switch toenergize the electrodes in the end effector 124.

Still with reference to FIG. 1, the generator 100 also is configured todrive a multifunction surgical instrument 108. The multifunctionsurgical instrument 108 comprises a handpiece 109 (HP), a shaft 129, andan end effector 125. The end effector comprises an ultrasonic blade 149and a clamp arm 146. The ultrasonic blade 149 is acoustically coupled tothe ultrasonic transducer 120. The handpiece 109 comprises a trigger 147to operate the clamp arm 146 and a combination of the toggle buttons 137a, 137 b, 137 c to energize and drive the ultrasonic blade 149 or otherfunction. The toggle buttons 137 a, 137 b, 137 c can be configured toenergize the ultrasonic transducer 120 with the generator 100 andenergize the ultrasonic blade 149 with a bipolar energy source alsocontained within the generator 100.

With reference to both FIGS. 1 and 2, the generator 100 is configurablefor use with a variety of surgical instruments. According to variousforms, the generator 100 may be configurable for use with differentsurgical instruments of different types including, for example, theultrasonic surgical instrument 104, the RF electrosurgical instrument106, and the multifunction surgical instrument 108 that integrate RF andultrasonic energies delivered simultaneously from the generator 100.Although in the form of FIG. 1, the generator 100 is shown separate fromthe surgical instruments 104, 106, 108, in one form, the generator 100may be formed integrally with any one of the surgical instruments 104,106, 108 to form a unitary surgical system. The generator 100 comprisesan input device 110 located on a front panel of the generator 100console. The input device 110 may comprise any suitable device thatgenerates signals suitable for programming the operation of thegenerator 100. The generator 100 also may comprise one or more outputdevices 112.

With reference now to FIG. 2, the generator 100 is coupled to themultifunction surgical instrument 108. The generator 100 is coupled tothe ultrasonic transducer 120 and electrodes located in the clamp arm146 via a cable 144. The ultrasonic transducer 120 and a waveguideextending through a shaft 129 (waveguide not shown in FIG. 2) maycollectively form an ultrasonic drive system driving an ultrasonic blade149 of an end effector 125. The end effector 125 further may comprise aclamp arm 146 to clamp tissue located between the clamp arm 146 and theultrasonic blade 149. The clamp arm 146 comprises one or more than onean electrode coupled to the a pole of the generator 100 (e.g., apositive pole). The ultrasonic blade 149 forms the second pole (e.g.,the negative pole) and is also coupled to the generator 100. RF energyis applied to the electrode(s) in the clamp arm 146, through the tissuelocated between the clamp arm 146 and the ultrasonic blade 149, andthrough the ultrasonic blade 149 back to the generator 100 via the cable144. In one form, the generator 100 may be configured to produce a drivesignal of a particular voltage, current, and/or frequency output signalthat can be varied or otherwise modified with high resolution, accuracy,and repeatability suitable for driving an ultrasonic transducer 120 andapplying RF energy to tissue.

Still with reference to FIG. 2, It will be appreciated that themultifunction surgical instrument 108 may comprise any combination ofthe toggle buttons 137 a, 137 b, 134 c. For example, the multifunctionsurgical instrument 108 could be configured to have only two togglebuttons: a toggle button 137 a for producing maximum ultrasonic energyoutput and a toggle button 137 b for producing a pulsed output at eitherthe maximum or less than maximum power level. In this way, the drivesignal output configuration of the generator 100 could be 5 continuoussignals and 5 or 4 or 3 or 2 or 1 pulsed signals. In certain forms, thespecific drive signal configuration may be controlled based upon, forexample, a non-volatile memory such as an electrically erasableprogrammable read only memory (EEPROM) settings in the generator 100and/or user power level selection(s).

In certain forms, a two-position switch may be provided as analternative to a toggle button 137 c. For example, the multifunctionsurgical instrument 108 may include a toggle button 137 a for producinga continuous output at a maximum power level and a two-position togglebutton 137 b. In a first detented position, toggle button 137 b mayproduce a continuous output at a less than maximum power level, and in asecond detented position the toggle button 137 b may produce a pulsedoutput (e.g., at either a maximum or less than maximum power level,depending upon the EEPROM settings). Any one of the buttons 137 a, 137b, 137 c may be configured to activate RF energy and apply the RF energyto the end effector 125.

Still with reference to FIG. 2, forms of the generator 100 may enablecommunication with instrument-based data circuits. For example, thegenerator 100 may be configured to communicate with a first data circuit136 and/or a second data circuit 138. For example, the first datacircuit 136 may indicate a burn-in frequency slope, as described herein.Additionally or alternatively, any type of information may becommunicated to second data circuit for storage therein via a datacircuit interface (e.g., using a logic device). Such information maycomprise, for example, an updated number of operations in which theinstrument has been used and/or dates and/or times of its usage. Incertain forms, the second data circuit may transmit data acquired by oneor more sensors (e.g., an instrument-based temperature sensor). Incertain forms, the second data circuit may receive data from thegenerator 100 and provide an indication to a user (e.g., a lightemitting diode (LED) indication or other visible indication) based onthe received data. The second data circuit 138 contained in themultifunction surgical instrument 108. In some forms, the second datacircuit 138 may be implemented in a many similar to that of the firstdata circuit 136 described herein. An instrument interface circuit maycomprise a second data circuit interface to enable this communication.In one form, the second data circuit interface may comprise a tri-statedigital interface, although other interfaces also may be used. Incertain forms, the second data circuit may generally be any circuit fortransmitting and/or receiving data. In one form, for example, the seconddata circuit may store information pertaining to the particular surgicalinstrument 104, 106, 108 with which it is associated. Such informationmay include, for example, a model number, a serial number, a number ofoperations in which the surgical instrument 104, 106, 108 has been used,and/or any other type of information. In the example of FIG. 2, thesecond data circuit 138 may store information about the electricaland/or ultrasonic properties of an associated ultrasonic transducer 120,end effector 125, ultrasonic energy drive system, or RF electrosurgicalenergy drive system. Various processes and techniques described hereinmay be executed by a generator. It will be appreciated, however, that incertain example forms, all or a part of these processes and techniquesmay be performed by internal logic 139 located in the multifunctionsurgical instrument 108.

FIG. 3 is a diagram of the surgical system 10 of FIG. 1. In variousforms, the generator 100 may comprise several separate functionalelements, such as modules and/or blocks. Different functional elementsor modules may be configured for driving the different kinds of surgicalinstruments 104, 106, 108. For example, an ultrasonic drive circuit 114may drive ultrasonic devices such as the surgical instrument 104 via acable 141. An electrosurgery/RF drive circuit 116 may drive the RFelectrosurgical instrument 106 via a cable 133. The respective drivecircuits 114, 116, 118 may be combined as a combined RF/ultrasonic drivecircuit 118 to generate both respective drive signals for drivingmultifunction surgical instruments 108 via a cable 144. In variousforms, the ultrasonic drive circuit 114 and/or the electrosurgery/RFdrive circuit 116 each may be formed integrally or externally with thegenerator 100. Alternatively, one or more of the drive circuits 114,116, 118 may be provided as a separate circuit module electricallycoupled to the generator 100. (The drive circuits 114, 116, 118 areshown in phantom to illustrate this option.) Also, in some forms, theelectrosurgery/RF drive circuit 116 may be formed integrally with theultrasonic drive circuit 114, or vice versa. Also, in some forms, thegenerator 100 may be omitted entirely and the drive circuits 114, 116,118 may be executed by processors or other hardware within therespective surgical instruments 104, 106, 108.

In other forms, the electrical outputs of the ultrasonic drive circuit114 and the electrosurgery/RF drive circuit 116 may be combined into asingle electrical signal capable of driving the multifunction surgicalinstrument 108 simultaneously with electrosurgical RF and ultrasonicenergies. This single electrical drive signal may be produced by thecombination drive circuit 118. The multifunction surgical instrument 108comprises an ultrasonic transducer 120 coupled to an ultrasonic bladeand one or more electrodes in the end effector 125 to receive ultrasonicand electrosurgical RF energy. The multifunction surgical instrument 108comprises signal processing components to split the combinedRF/ultrasonic energy signal such that the RF signal can be delivered tothe electrodes in the end effector 125 and the ultrasonic signal can bedelivered to the ultrasonic transducer 120.

In accordance with the described forms, the ultrasonic drive circuit 114may produce a drive signal or signals of particular voltages, currents,and frequencies, e.g., 55,500 cycles per second (Hz). The drive signalor signals may be provided to the ultrasonic surgical instrument 104,and specifically to the ultrasonic transducer 120, which may operate,for example, as described above. The ultrasonic transducer 120 and awaveguide extending through the shaft 126 (waveguide not shown) maycollectively form an ultrasonic drive system driving an ultrasonic blade128 of an end effector 122. In one form, the generator 100 may beconfigured to produce a drive signal of a particular voltage, current,and/or frequency output signal that can be stepped or otherwise modifiedwith high resolution, accuracy, and repeatability.

The generator 100 may be activated to provide the drive signal to theultrasonic transducer 120 in any suitable manner. For example, thegenerator 100 may comprise a foot switch 130 coupled to the generator100 via a foot switch cable 132. A clinician may activate the ultrasonictransducer 120 by depressing the foot switch 130. In addition, orinstead of the foot switch 130 some forms of the ultrasonic surgicalinstrument 104 may utilize one or more switches positioned on thehandpiece that, when activated, may cause the generator 100 to activatethe ultrasonic transducer 120. In one form, for example, the one or moreswitches may comprise a pair of toggle buttons 137 a, 137 b (FIG. 2),for example, to determine an operating mode of the ultrasonic surgicalinstrument 104. When the toggle button 137 a is depressed, for example,the generator 100 may provide a maximum drive signal to the ultrasonictransducer 120, causing it to produce maximum ultrasonic energy output.Depressing toggle button 137 b may cause the generator 100 to provide auser-selectable drive signal to the ultrasonic transducer 120, causingit to produce less than the maximum ultrasonic energy output.

Additionally or alternatively, the one or more switches may comprise atoggle button 137 c that, when depressed, causes the generator 100 toprovide a pulsed output. The pulses may be provided at any suitablefrequency and grouping, for example. In certain forms, the power levelof the pulses may be the power levels associated with toggle buttons 137a, 137 b (maximum, less than maximum), for example.

It will be appreciated that the ultrasonic surgical instrument 104and/or the multifunction surgical instrument 108 may comprise anycombination of the toggle buttons 137 a, 137 b, 137 c. For example, themultifunction surgical instrument 108 could be configured to have onlytwo toggle buttons: a toggle button 137 a for producing maximumultrasonic energy output and a toggle button 137 c for producing apulsed output at either the maximum or less than maximum power level. Inthis way, the drive signal output configuration of the generator 100could be 5 continuous signals and 5 or 4 or 3 or 2 or 1 pulsed signals.In certain forms, the specific drive signal configuration may becontrolled based upon, for example, EEPROM settings in the generator 100and/or user power level selection(s).

In certain forms, a two-position switch may be provided as analternative to a toggle button 137 c. For example, the ultrasonicsurgical instrument 104 may include a toggle button 137 a for producinga continuous output at a maximum power level and a two-position togglebutton 137 b. In a first detented position, toggle button 137 b mayproduce a continuous output at a less than maximum power level, and in asecond detented position the toggle button 137 b may produce a pulsedoutput (e.g., at either a maximum or less than maximum power level,depending upon the EEPROM settings).

In accordance with the described forms, the electrosurgery/RF drivecircuit 116 may generate a drive signal or signals with output powersufficient to perform bipolar electrosurgery using RF energy. In bipolarelectrosurgery applications, the drive signal may be provided, forexample, to electrodes located in the end effector 124 of the RFelectrosurgical instrument 106, for example. Accordingly, the generator100 may be configured for therapeutic purposes by applying electricalenergy to the tissue sufficient for treating the tissue (e.g.,coagulation, cauterization, tissue welding). The generator 100 may beconfigured for sub-therapeutic purposes by applying electrical energy tothe tissue for monitoring parameters of the tissue during a procedure.

As previously discussed, the combination drive circuit 118 may beconfigured to drive both ultrasonic and RF electrosurgical energies. Theultrasonic and RF electrosurgical energies may be delivered thoughseparate output ports of the generator 100 as separate signals or thougha single port of the generator 100 as a single signal that is acombination of the ultrasonic and RF electrosurgical energies. In thelatter case, the single signal can be separated by circuits located inthe surgical instruments 104, 106, 108.

The surgical instruments 104, 106, 108 additionally or alternatively maycomprise a switch to indicate a position of a jaw closure trigger foroperating jaws of the end effector 122, 124, 125. Also, in some forms,the generator 100 may be activated based on the position of the jawclosure trigger, (e.g., as the clinician depresses the jaw closuretrigger to close the jaws, ultrasonic energy may be applied).

The generator 100 may comprise an input device 110 (FIG. 1) located, forexample, on a front panel of the generator 100 console. The input device110 may comprise any suitable device that generates signals suitable forprogramming the operation of the generator 100. In operation, the usercan program or otherwise control operation of the generator 100 usingthe input device 110. The input device 110 may comprise any suitabledevice that generates signals that can be used by the generator (e.g.,by one or more processors contained in the generator) to control theoperation of the generator 100 (e.g., operation of the ultrasonic drivecircuit 114, electrosurgery/RF drive circuit 116, combined RF/ultrasonicdrive circuit 118). In various forms, the input device 110 includes oneor more of buttons, switches, thumbwheels, keyboard, keypad, touchscreen monitor, pointing device, remote connection to a general purposeor dedicated computer. In other forms, the input device 110 may comprisea suitable user interface, such as one or more user interface screensdisplayed on a touch screen monitor, for example. Accordingly, by way ofthe input device 110, the user can set or program various operatingparameters of the generator, such as, for example, current (I), voltage(V), frequency (f), and/or period (T) of a drive signal or signalsgenerated by the ultrasonic drive circuit 114 and/or electrosurgery/RFdrive circuit 116.

The generator 100 also may comprise an output device 112 (FIG. 1), suchas an output indicator, located, for example, on a front panel of thegenerator 100 console. The output device 112 includes one or moredevices for providing a sensory feedback to a user. Such devices maycomprise, for example, visual feedback devices (e.g., a visual feedbackdevice may comprise incandescent lamps, LEDs, graphical user interface,display, analog indicator, digital indicator, bar graph display, digitalalphanumeric display, liquid crystal display (LCD) screen, lightemitting diode (LED) indicators), audio feedback devices (e.g., an audiofeedback device may comprise speaker, buzzer, audible, computergenerated tone, computerized speech, voice user interface (VUI) tointeract with computers through a voice/speech platform), or tactilefeedback devices (e.g., a tactile feedback device comprises any type ofvibratory feedback, haptic actuator).

Although certain modules and/or blocks of the generator 100 may bedescribed by way of example, it can be appreciated that a greater orlesser number of modules and/or blocks may be used and still fall withinthe scope of the forms. Further, although various forms may be describedin terms of modules and/or blocks to facilitate description, suchmodules and/or blocks may be implemented by one or more hardwarecomponents, e.g., processors, Digital Signal Processors (DSPs),Programmable Logic Devices (PLDs), Application Specific IntegratedCircuits (ASICs), circuits, registers and/or software components, e.g.,programs, subroutines, logic and/or combinations of hardware andsoftware components. Also, in some forms, the various modules describedherein may be implemented utilizing similar hardware positioned withinthe surgical instruments 104, 106, 108 (i.e., the external generator 100may be omitted).

In one form, the ultrasonic drive circuit 114, electrosurgery/RF drivecircuit 116, and/or the combination drive circuit 118 may comprise oneor more embedded applications implemented as firmware, software,hardware, or any combination thereof. The drive circuits 114, 116, 118may comprise various executable modules such as software, programs,data, drivers, application program interfaces (APIs), and so forth. Thefirmware may be stored in nonvolatile memory (NVM), such as in bitmasked read-only memory (ROM) or flash memory. In variousimplementations, storing the firmware in ROM may preserve flash memory.The NVM may comprise other types of memory including, for example,programmable ROM (PROM), erasable programmable ROM (EPROM), EEPROM, orbattery backed random-access memory (RAM) such as dynamic RAM (DRAM),Double-Data-Rate DRAM (DDRAM), and/or synchronous DRAM (SDRAM).

In one form, the drive circuits 114, 116, 118 comprise a hardwarecomponent implemented as a processor for executing program instructionsfor monitoring various measurable characteristics of the surgicalinstruments 104, 106, 108 and generating a corresponding output controlsignals for operating the surgical instruments 104, 106, 108. In formsin which the generator 100 is used in conjunction with the multifunctionsurgical instrument 108, the output control signal may drive theultrasonic transducer 120 in cutting and/or coagulation operating modes.Electrical characteristics of the multifunction surgical instrument 108and/or tissue may be measured and used to control operational aspects ofthe generator 100 and/or provided as feedback to the user. In forms inwhich the generator 100 is used in conjunction with the multifunctionsurgical instrument 108, the output control signal may supply electricalenergy (e.g., RF energy) to the end effector 125 in cutting, coagulationand/or desiccation modes. Electrical characteristics of themultifunction surgical instrument 108 and/or tissue may be measured andused to control operational aspects of the generator 100 and/or providefeedback to the user. In various forms, as previously discussed, thehardware component may be implemented as a DSP, PLD, ASIC, circuits,and/or registers. In one form, the processor may be configured to storeand execute computer software program instructions to generate theoutput signals for driving various components of the surgicalinstruments 104, 106, 108, such as the ultrasonic transducer 120 and theend effectors 122, 124, 125.

FIG. 4 illustrates an equivalent circuit 150 of an ultrasonictransducer, such as the ultrasonic transducer 120, according to oneform. The equivalent circuit 150 comprises a first “motional” branchhaving a serially connected inductance L_(s), resistance R_(s) andcapacitance C_(s) that define the electromechanical properties of theresonator, and a second capacitive branch having a static capacitanceC_(o). Drive current I_(g) may be received from a generator at a drivevoltage V_(g), with motional current I_(m) flowing through the firstbranch and current I_(g)−I_(m) flowing through the capacitive branch.Control of the electromechanical properties of the ultrasonic transducermay be achieved by suitably controlling I_(g) and V_(g). As explainedabove, conventional generator architectures may include a tuninginductor L_(t) (shown in phantom in FIG. 4) for tuning out in a parallelresonance circuit the static capacitance Co at a resonant frequency sothat substantially all of generator's current output I_(g) flows throughthe motional branch. In this way, control of the motional branch currentI_(m) is achieved by controlling the generator current output I_(g). Thetuning inductor L_(t) is specific to the static capacitance C_(o) of anultrasonic transducer, however, and a different ultrasonic transducerhaving a different static capacitance requires a different tuninginductor L_(t). Moreover, because the tuning inductor L_(t) is matchedto the nominal value of the static capacitance Co at a single resonantfrequency, accurate control of the motional branch current I_(m) isassured only at that frequency, and as frequency shifts down withtransducer temperature, accurate control of the motional branch currentis compromised.

Forms of the generator 100 do not rely on a tuning inductor L_(t) tomonitor the motional branch current I_(m). Instead, the generator 100may use the measured value of the static capacitance C_(o) in betweenapplications of power for a specific ultrasonic surgical instrument 104(along with drive signal voltage and current feedback data) to determinevalues of the motional branch current I_(m) on a dynamic and ongoingbasis (e.g., in real-time). Such forms of the generator 100 aretherefore able to provide virtual tuning to simulate a system that istuned or resonant with any value of static capacitance C_(o) at anyfrequency, and not just at single resonant frequency dictated by anominal value of the static capacitance C_(o).

FIG. 5 is a simplified block diagram of a generator 200, which is oneform of the generator 100 (FIGS. 1-3). The generator 200 is configuredto provide inductorless tuning as described above, among other benefits.Additional details of the generator 200 are described in commonlyassigned and contemporaneously filed U.S. Pat. No. 9,060,775, titledSURGICAL GENERATOR FOR ULTRASONIC AND ELECTROSURGICAL DEVICES, thedisclosure of which is incorporated herein by reference in its entirety.With reference to FIG. 5, the generator 200 may comprise a patientisolated stage 202 in communication with a non-isolated stage 204 via apower transformer 206. A secondary winding 208 of the power transformer206 is contained in the isolated stage 202 and may comprise a tappedconfiguration (e.g., a center-tapped or a non-center-tappedconfiguration) to define drive signal outputs 210 a, 210 b, 210 c fordelivering drive signals to different surgical instruments, such as, forexample, an ultrasonic surgical instrument 104, an RF electrosurgicalinstrument 106, and a multifunction surgical instrument 108. Inparticular, drive signal outputs 210 a, 210 c may output an ultrasonicdrive signal (e.g., a 420V root-mean-square [RMS] drive signal) to anultrasonic surgical instrument 104, and drive signal outputs 210 b, 210c may output an electrosurgical drive signal (e.g., a 100V RMS drivesignal) to an RF electrosurgical instrument 106, with the drive signaloutput 2160 b corresponding to the center tap of the power transformer206.

In certain forms, the ultrasonic and electrosurgical drive signals maybe provided simultaneously to distinct surgical instruments and/or to asingle surgical instrument having the capability to deliver bothultrasonic and electrosurgical energy to tissue, such as themultifunction surgical instrument 108 (FIGS. 1-3). It will beappreciated that the electrosurgical signal, provided either to adedicated electrosurgical instrument and/or to a combined multifunctionultrasonic/electrosurgical instrument may be either a therapeutic orsub-therapeutic level signal where the sub-therapeutic signal can beused, for example, to monitor tissue or instrument conditions andprovide feedback to the generator. For example, the ultrasonic and RFsignals can be delivered separately or simultaneously from a generatorwith a single output port in order to provide the desired output signalto the surgical instrument, as will be discussed in more detail below.Accordingly, the generator can combine the ultrasonic andelectrosurgical RF energies and deliver the combined energies to themultifunction ultrasonic/electrosurgical instrument. Bipolar electrodescan be placed on one or both jaws of the end effector. One jaw may bedriven by ultrasonic energy in addition to electrosurgical RF energy,working simultaneously. The ultrasonic energy may be employed to dissecttissue while the electrosurgical RF energy may be employed for vesselsealing.

The non-isolated stage 204 may comprise a power amplifier 212 having anoutput connected to a primary winding 214 of the power transformer 206.In certain forms the power amplifier 212 may be comprise a push-pullamplifier. For example, the non-isolated stage 204 may further comprisea logic device 216 for supplying a digital output to a digital-to-analogconverter (DAC) circuit 218, which in turn supplies a correspondinganalog signal to an input of the power amplifier 212. In certain formsthe logic device 216 may comprise a programmable gate array (PGA), afield programmable gate array (FPGA), programmable logic device (PLD),among other logic circuits, for example. The logic device 216, by virtueof controlling the input of the power amplifier 212 via the DAC circuit218, may therefore control any of a number of parameters (e.g.,frequency, waveform shape, waveform amplitude) of drive signalsappearing at the drive signal outputs 210 a, 210 b, 210 c. In certainforms and as discussed below, the logic device 216, in conjunction witha processor (e.g., a digital signal processor discussed below), mayimplement a number of digital signal processing (DSP)-based and/or othercontrol algorithms to control parameters of the drive signals output bythe generator 200.

Power may be supplied to a power rail of the power amplifier 212 by aswitch-mode regulator 220, e.g., power converter. In certain forms theswitch-mode regulator 220 may comprise an adjustable buck regulator, forexample. The non-isolated stage 204 may further comprise a firstprocessor 222, which in one form may comprise a DSP processor such as anAnalog Devices ADSP-21469 SHARC DSP, available from Analog Devices,Norwood, Mass., for example, although in various forms any suitableprocessor may be employed. In certain forms the DSP processor 222 maycontrol operation of the switch-mode regulator 220 responsive to voltagefeedback data received from the power amplifier 212 by the DSP processor222 via an analog-to-digital converter (ADC) circuit 224. In one form,for example, the DSP processor 222 may receive as input, via the ADCcircuit 224, the waveform envelope of a signal (e.g., an RF signal)being amplified by the power amplifier 212. The DSP processor 222 maythen control the switch-mode regulator 220 (e.g., via a pulse-widthmodulated (PWM) output) such that the rail voltage supplied to the poweramplifier 212 tracks the waveform envelope of the amplified signal. Bydynamically modulating the rail voltage of the power amplifier 212 basedon the waveform envelope, the efficiency of the power amplifier 212 maybe significantly improved relative to a fixed rail voltage amplifierschemes.

In certain forms, the logic device 216, in conjunction with the DSPprocessor 222, may implement a digital synthesis circuit such as a DDS(see e.g., FIGS. 13, 14) control scheme to control the waveform shape,frequency and/or amplitude of drive signals output by the generator 200.In one form, for example, the logic device 216 may implement a DDScontrol algorithm by recalling waveform samples stored in adynamically-updated lookup table (LUT), such as a RAM LUT, which may beembedded in an FPGA. This control algorithm is particularly useful forultrasonic applications in which an ultrasonic transducer, such as theultrasonic transducer 120, may be driven by a clean sinusoidal currentat its resonant frequency. Because other frequencies may exciteparasitic resonances, minimizing or reducing the total distortion of themotional branch current may correspondingly minimize or reduceundesirable resonance effects. Because the waveform shape of a drivesignal output by the generator 200 is impacted by various sources ofdistortion present in the output drive circuit (e.g., the powertransformer 206, the power amplifier 212), voltage and current feedbackdata based on the drive signal may be input into an algorithm, such asan error control algorithm implemented by the DSP processor 222, whichcompensates for distortion by suitably pre-distorting or modifying thewaveform samples stored in the LUT on a dynamic, ongoing basis (e.g., inreal-time). In one form, the amount or degree of pre-distortion appliedto the LUT samples may be based on the error between a computed motionalbranch current and a desired current waveform shape, with the errorbeing determined on a sample-by-sample basis. In this way, thepre-distorted LUT samples, when processed through the drive circuit, mayresult in a motional branch drive signal having the desired waveformshape (e.g., sinusoidal) for optimally driving the ultrasonictransducer. In such forms, the LUT waveform samples will therefore notrepresent the desired waveform shape of the drive signal, but rather thewaveform shape that is required to ultimately produce the desiredwaveform shape of the motional branch drive signal when distortioneffects are taken into account.

The non-isolated stage 204 may further comprise a first ADC circuit 226and a second ADC circuit 228 coupled to the output of the powertransformer 206 via respective isolation transformers 230, 232 forrespectively sampling the voltage and current of drive signals output bythe generator 200. In certain forms, the ADC circuits 226, 228 may beconfigured to sample at high speeds (e.g., 80 mega samples per second[MSPS]) to enable oversampling of the drive signals. In one form, forexample, the sampling speed of the ADC circuits 226, 228 may enableapproximately 200× (depending on frequency) oversampling of the drivesignals. In certain forms, the sampling operations of the ADC circuit226, 228 may be performed by a single ADC circuit receiving inputvoltage and current signals via a two-way multiplexer. The use ofhigh-speed sampling in forms of the generator 200 may enable, amongother things, calculation of the complex current flowing through themotional branch (which may be used in certain forms to implement directdigital synthesis (DDS) based waveform shape control described above),accurate digital filtering of the sampled signals, and calculation ofreal power consumption with a high degree of precision. Voltage andcurrent feedback data output by the ADC circuits 226, 228 may bereceived and processed (e.g., first-in-first-out [FIFO] buffer,multiplexer, etc.) by the logic device 216 and stored in data memory forsubsequent retrieval by, for example, the DSP processor 222. As notedabove, voltage and current feedback data may be used as input to analgorithm for pre-distorting or modifying LUT waveform samples on adynamic and ongoing basis. In certain forms, this may require eachstored voltage and current feedback data pair to be indexed based on, orotherwise associated with, a corresponding LUT sample that was output bythe logic device 216 when the voltage and current feedback data pair wasacquired. Synchronization of the LUT samples and the voltage and currentfeedback data in this manner contributes to the correct timing andstability of the pre-distortion algorithm.

In certain forms, the voltage and current feedback data may be used tocontrol the frequency and/or amplitude (e.g., current amplitude) of thedrive signals. In one form, for example, voltage and current feedbackdata may be used to determine impedance phase. The frequency of thedrive signal may then be controlled to minimize or reduce the differencebetween the determined impedance phase and an impedance phase setpoint(e.g., 0°), thereby minimizing or reducing the effects of harmonicdistortion and correspondingly enhancing impedance phase measurementaccuracy. The determination of phase impedance and a frequency controlsignal may be implemented in the DSP processor 222, for example, withthe frequency control signal being supplied as input to a DDS controlalgorithm implemented by the logic device 216.

In another form, for example, the current feedback data may be monitoredin order to maintain the current amplitude of the drive signal at acurrent amplitude setpoint. The current amplitude setpoint may bespecified directly or determined indirectly based on specified voltageamplitude and power setpoints. In certain forms, control of the currentamplitude may be implemented by control algorithm, such as, for example,a proportional-integral-derivative (PID) control algorithm, in the DSPprocessor 222. Variables controlled by the control algorithm to suitablycontrol the current amplitude of the drive signal may include, forexample, the scaling of the LUT waveform samples stored in the logicdevice 216 and/or the full-scale output voltage of the DAC circuit 218(which supplies the input to the power amplifier 212) via a DAC circuit234.

The non-isolated stage 204 may further comprise a second processor 236for providing, among other things user interface (UI) functionality. Inone form, the UI processor 236 may comprise an Atmel AT91SAM9263processor having an ARM 926EJ-S core, available from Atmel Corporation,San Jose, Calif., for example. Examples of UI functionality supported bythe UI processor 236 may include audible and visual user feedback,communication with peripheral devices (e.g., via a Universal Serial Bus[USB] interface), communication with the foot switch 130, communicationwith an input device 110 (e.g., a touch screen display) andcommunication with an output device 112 (e.g., a speaker), as shown inFIGS. 1 and 3. The UI processor 236 may communicate with the DSPprocessor 222 and the logic device 216 (e.g., via serial peripheralinterface [SPI] buses). Although the UI processor 236 may primarilysupport UI functionality, it may also coordinate with the DSP processor222 to implement hazard mitigation in certain forms. For example, the UIprocessor 236 may be programmed to monitor various aspects of user inputand/or other inputs (e.g., touch screen inputs, foot switch 130 inputsas shown in FIG. 3, temperature sensor inputs) and may disable the driveoutput of the generator 200 when an erroneous condition is detected.

In certain forms, both the DSP processor 222 and the UI processor 236,for example, may determine and monitor the operating state of thegenerator 200. For the DSP processor 222, the operating state of thegenerator 200 may dictate, for example, which control and/or diagnosticprocesses are implemented by the DSP processor 222. For the UI processor236, the operating state of the generator 200 may dictate, for example,which elements of a user interface (e.g., display screens, sounds) arepresented to a user. The respective DSP and UI processors 222, 236 mayindependently maintain the current operating state of the generator 200and recognize and evaluate possible transitions out of the currentoperating state. The DSP processor 222 may function as the master inthis relationship and determine when transitions between operatingstates are to occur. The UI processor 236 may be aware of validtransitions between operating states and may confirm if a particulartransition is appropriate. For example, when the DSP processor 222instructs the UI processor 236 to transition to a specific state, the UIprocessor 236 may verify that requested transition is valid. In theevent that a requested transition between states is determined to beinvalid by the UI processor 236, the UI processor 236 may cause thegenerator 200 to enter a failure mode.

The non-isolated stage 204 may further comprise a controller 238 formonitoring input devices 110 (e.g., a capacitive touch sensor used forturning the generator 200 on and off, a capacitive touch screen). Incertain forms, the controller 238 may comprise at least one processorand/or other controller device in communication with the UI processor236. In one form, for example, the controller 238 may comprise aprocessor (e.g., a Mega168 8-bit controller available from Atmel)configured to monitor user input provided via one or more capacitivetouch sensors. In one form, the controller 238 may comprise a touchscreen controller (e.g., a QT5480 touch screen controller available fromAtmel) to control and manage the acquisition of touch data from acapacitive touch screen.

In certain forms, when the generator 200 is in a “power off” state, thecontroller 238 may continue to receive operating power (e.g., via a linefrom a power supply of the generator 200, such as the power supply 254discussed below). In this way, the controller 196 may continue tomonitor an input device 110 (e.g., a capacitive touch sensor located ona front panel of the generator 200) for turning the generator 200 on andoff. When the generator 200 is in the power off state, the controller238 may wake the power supply (e.g., enable operation of one or moreDC/DC voltage converters 256 of the power supply 254) if activation ofthe “on/off” input device 110 by a user is detected. The controller 238may therefore initiate a sequence for transitioning the generator 200 toa “power on” state. Conversely, the controller 238 may initiate asequence for transitioning the generator 200 to the power off state ifactivation of the “on/off” input device 110 is detected when thegenerator 200 is in the power on state. In certain forms, for example,the controller 238 may report activation of the “on/off” input device110 to the UI processor 236, which in turn implements the necessaryprocess sequence for transitioning the generator 200 to the power offstate. In such forms, the controller 196 may have no independent abilityfor causing the removal of power from the generator 200 after its poweron state has been established.

In certain forms, the controller 238 may cause the generator 200 toprovide audible or other sensory feedback for alerting the user that apower on or power off sequence has been initiated. Such an alert may beprovided at the beginning of a power on or power off sequence and priorto the commencement of other processes associated with the sequence.

In certain forms, the isolated stage 202 may comprise an instrumentinterface circuit 240 to, for example, provide a communication interfacebetween a control circuit of a surgical instrument (e.g., a controlcircuit comprising handpiece switches) and components of thenon-isolated stage 204, such as, for example, the logic device 216, theDSP processor 222 and/or the UI processor 236. The instrument interfacecircuit 240 may exchange information with components of the non-isolatedstage 204 via a communication link that maintains a suitable degree ofelectrical isolation between the isolated and non-isolated stages 202,204, such as, for example, an infrared (IR)-based communication link.Power may be supplied to the instrument interface circuit 240 using, forexample, a low-dropout voltage regulator powered by an isolationtransformer driven from the non-isolated stage 204.

In one form, the instrument interface circuit 240 may comprise a logiccircuit 242 (e.g., logic circuit, programmable logic circuit, PGA, FPGA,PLD) in communication with a signal conditioning circuit 244. The signalconditioning circuit 244 may be configured to receive a periodic signalfrom the logic circuit 242 (e.g., a 2 kHz square wave) to generate abipolar interrogation signal having an identical frequency. Theinterrogation signal may be generated, for example, using a bipolarcurrent source fed by a differential amplifier. The interrogation signalmay be communicated to a surgical instrument control circuit (e.g., byusing a conductive pair in a cable that connects the generator 200 tothe surgical instrument) and monitored to determine a state orconfiguration of the control circuit. The control circuit may comprise anumber of switches, resistors and/or diodes to modify one or morecharacteristics (e.g., amplitude, rectification) of the interrogationsignal such that a state or configuration of the control circuit isuniquely discernable based on the one or more characteristics. In oneform, for example, the signal conditioning circuit 244 may comprise anADC circuit for generating samples of a voltage signal appearing acrossinputs of the control circuit resulting from passage of interrogationsignal therethrough. The logic circuit 242 (or a component of thenon-isolated stage 204) may then determine the state or configuration ofthe control circuit based on the ADC circuit samples.

In one form, the instrument interface circuit 240 may comprise a firstdata circuit interface 246 to enable information exchange between thelogic circuit 242 (or other element of the instrument interface circuit240) and a first data circuit disposed in or otherwise associated with asurgical instrument. In certain forms, for example, a first data circuit136 (FIG. 2) may be disposed in a cable integrally attached to asurgical instrument handpiece, or in an adaptor for interfacing aspecific surgical instrument type or model with the generator 200. Thefirst data circuit 136 may be implemented in any suitable manner and maycommunicate with the generator according to any suitable protocolincluding, for example, as described herein with respect to the firstdata circuit 136. In certain forms, the first data circuit may comprisea non-volatile storage device, such as an EEPROM device. In certainforms and referring again to FIG. 5, the first data circuit interface246 may be implemented separately from the logic circuit 242 andcomprise suitable circuitry (e.g., discrete logic devices, a processor)to enable communication between the logic circuit 242 and the first datacircuit. In other forms, the first data circuit interface 246 may beintegral with the logic circuit 242.

In certain forms, the first data circuit 136 *FIG. 2) may storeinformation pertaining to the particular surgical instrument with whichit is associated. Such information may include, for example, a modelnumber, a serial number, a number of operations in which the surgicalinstrument has been used, and/or any other type of information. Thisinformation may be read by the instrument interface circuit 240 (e.g.,by the logic circuit 242), transferred to a component of thenon-isolated stage 204 (e.g., to logic device 216, DSP processor 222and/or UI processor 236) for presentation to a user via an output device112 (FIGS. 1 and 3) and/or for controlling a function or operation ofthe generator 200. Additionally, any type of information may becommunicated to first data circuit 136 for storage therein via the firstdata circuit interface 246 (e.g., using the logic circuit 242). Suchinformation may comprise, for example, an updated number of operationsin which the surgical instrument has been used and/or dates and/or timesof its usage.

As discussed previously, a surgical instrument may be detachable from ahandpiece (e.g., the multifunction surgical instrument 108 may bedetachable from the handpiece 109) to promote instrumentinterchangeability and/or disposability. In such cases, conventionalgenerators may be limited in their ability to recognize particularinstrument configurations being used and to optimize control anddiagnostic processes accordingly. The addition of readable data circuitsto surgical instruments to address this issue is problematic from acompatibility standpoint, however. For example, designing a surgicalinstrument to remain backwardly compatible with generators that lack therequisite data reading functionality may be impractical due to, forexample, differing signal schemes, design complexity, and cost. Forms ofinstruments discussed herein address these concerns by using datacircuits that may be implemented in existing surgical instrumentseconomically and with minimal design changes to preserve compatibilityof the surgical instruments with current generator platforms.

Additionally, forms of the generator 200 may enable communication withinstrument-based data circuits. For example, the generator 200 may beconfigured to communicate with a second data circuit 138 (FIG. 2)contained in an instrument (e.g., the multifunction surgical instrument108 shown in FIG. 2). In some forms, the second data circuit 138 may beimplemented in a many similar to that of the first data circuit 136(FIG. 2) described herein. The instrument interface circuit 240 maycomprise a second data circuit interface 248 to enable thiscommunication. In one form, the second data circuit interface 248 maycomprise a tri-state digital interface, although other interfaces mayalso be used. In certain forms, the second data circuit may generally beany circuit for transmitting and/or receiving data. In one form, forexample, the second data circuit may store information pertaining to theparticular surgical instrument with which it is associated. Suchinformation may include, for example, a model number, a serial number, anumber of operations in which the surgical instrument has been used,and/or any other type of information.

In some forms, the second data circuit 138 (FIG. 2) may storeinformation about the electrical and/or ultrasonic properties of anassociated ultrasonic transducer 120, end effector 125, or ultrasonicdrive system. For example, the first data circuit 136 (FIG. 2) mayindicate a burn-in frequency slope, as described herein. Additionally oralternatively, any type of information may be communicated to seconddata circuit for storage therein via the second data circuit interface248 (e.g., using the logic circuit 242). Such information may comprise,for example, an updated number of operations in which the instrument hasbeen used and/or dates and/or times of its usage. In certain forms, thesecond data circuit may transmit data acquired by one or more sensors(e.g., an instrument-based temperature sensor). In certain forms, thesecond data circuit may receive data from the generator 200 and providean indication to a user (e.g., a light emitting diode [LED] indicationor other visible indication) based on the received data.

In certain forms, the second data circuit and the second data circuitinterface 248 may be configured such that communication between thelogic circuit 242 and the second data circuit can be effected withoutthe need to provide additional conductors for this purpose (e.g.,dedicated conductors of a cable connecting a handpiece to the generator200). In one form, for example, information may be communicated to andfrom the second data circuit using a 1-wire bus communication schemeimplemented on existing cabling, such as one of the conductors usedtransmit interrogation signals from the signal conditioning circuit 244to a control circuit in a handpiece. In this way, design changes ormodifications to the surgical instrument that might otherwise benecessary are minimized or reduced. Moreover, because different types ofcommunications implemented over a common physical channel can befrequency-band separated, the presence of a second data circuit may be“invisible” to generators that do not have the requisite data readingfunctionality, thus enabling backward compatibility of the surgicalinstrument.

In certain forms, the isolated stage 202 may comprise at least oneblocking capacitor 250-1 connected to the drive signal output 210 b toprevent passage of DC current to a patient. A single blocking capacitormay be required to comply with medical regulations or standards, forexample. While failure in single-capacitor designs is relativelyuncommon, such failure may nonetheless have negative consequences. Inone form, a second blocking capacitor 250-2 may be provided in serieswith the blocking capacitor 250-1, with current leakage from a pointbetween the blocking capacitors 250-1, 250-2 being monitored by, forexample, an ADC circuit 252 for sampling a voltage induced by leakagecurrent. The samples may be received by the logic circuit 242, forexample. Based changes in the leakage current (as indicated by thevoltage samples in the form of FIG. 5), the generator 200 may determinewhen at least one of the blocking capacitors 250-1, 250-2 has failed.Accordingly, the form of FIG. 5 provides a benefit over single-capacitordesigns having a single point of failure.

In certain forms, the non-isolated stage 204 may comprise a power supply254 for delivering DC power at a suitable voltage and current. The powersupply may comprise, for example, a 400 W power supply for delivering a48 VDC system voltage. The power supply 254 may further comprise one ormore DC/DC voltage converters 256 for receiving the output of the powersupply to generate DC outputs at the voltages and currents required bythe various components of the generator 200. As discussed above inconnection with the controller 238, one or more of the DC/DC voltageconverters 256 may receive an input from the controller 238 whenactivation of the “on/off” input device 110 by a user is detected by thecontroller 238 to enable operation of, or wake, the DC/DC voltageconverters 256.

FIG. 6 illustrates one form of a drive system 302 of a generator 300,which is one form of the generator 100 (FIGS. 1-3). The generator 300 isconfigured to provide an ultrasonic electrical signal for driving anultrasonic transducer (e.g., ultrasonic transducer 120 FIGS. 1-3), alsoreferred to as a drive signal. The generator 300 is similar to and maybe interchangeable with the generators 100, 200 (FIGS. 1-3 and 5). Thedrive system 302 is flexible and can create an ultrasonic electricaldrive signal 304 at a desired frequency and power level setting fordriving the ultrasonic transducer 306. In various forms, the generator300 may comprise several separate functional elements, such as modulesand/or blocks. Although certain modules and/or blocks may be describedby way of example, it can be appreciated that a greater or lesser numberof modules and/or blocks may be used and still fall within the scope ofthe forms. Further, although various forms may be described in terms ofmodules and/or blocks to facilitate description, such modules and/orblocks may be implemented by one or more hardware components, e.g.,processors, Digital Signal Processors (DSPs), Programmable Logic Devices(PLDs), Application Specific Integrated Circuits (ASICs), circuits,registers and/or software components, e.g., programs, subroutines, logicand/or combinations of hardware and software components.

In one form, the generator 300 drive system 302 may comprise one or moreembedded applications implemented as firmware, software, hardware, orany combination thereof. The generator 300 drive system 302 may comprisevarious executable modules such as software, programs, data, drivers,application program interfaces (APIs), and so forth. The firmware may bestored in nonvolatile memory (NVM), such as in bit-masked read-onlymemory (ROM) or flash memory. In various implementations, storing thefirmware in ROM may preserve flash memory. The NVM may comprise othertypes of memory including, for example, programmable ROM (PROM),erasable programmable ROM (EPROM), EEPROM, or battery backedrandom-access memory (RAM) such as dynamic RAM (DRAM), Double-Data-RateDRAM (DDRAM), and/or synchronous DRAM (SDRAM).

In one form, the generator 300 drive system 302 comprises a hardwarecomponent implemented as a processor 308 for executing programinstructions for monitoring various measurable characteristics of theultrasonic surgical instrument 104 (FIG. 1) and generating an outputsignal for driving the ultrasonic transducer in cutting and/orcoagulation operating modes. It will be appreciated by those skilled inthe art that the generator 300 and the drive system 302 may compriseadditional or fewer components and only a simplified version of thegenerator 300 and the drive system 302 are described herein forconciseness and clarity. In various forms, as previously discussed, thehardware component may be implemented as a DSP, PLD, ASIC, circuits,and/or registers. In one form, the processor 308 may be configured tostore and execute computer software program instructions to generate theoutput signals for driving various components of the ultrasonic surgicalinstrument 104, such as a transducer, an end effector, and/or a blade.

In one form, under control of one or more software program routines, theprocessor 308 executes the methods in accordance with the describedforms to generate an electrical signal output waveform comprisingcurrent (I), voltage (V), and/or frequency (f) for various timeintervals or periods (T). The stepwise waveforms of the drive signalsmay be generated by forming a piecewise linear combination of constantfunctions over a plurality of time intervals created by stepping thegenerator 300 drive signals, e.g., output drive current (I), voltage(V), and/or frequency (f). The time intervals or periods (T) may bepredetermined (e.g., fixed and/or programmed by the user) or may bevariable. Variable time intervals may be defined by setting the drivesignal to a first value and maintaining the drive signal at that valueuntil a change is detected in a monitored characteristic. Examples ofmonitored characteristics may comprise, for example, transducerimpedance, tissue impedance, tissue heating, tissue transection, tissuecoagulation, and the like. The ultrasonic drive signals generated by thegenerator 300 include, without limitation, ultrasonic drive signalscapable of exciting the ultrasonic transducer 306 in various vibratorymodes such as, for example, the primary longitudinal mode and harmonicsthereof as well flexural and torsional vibratory modes.

In one form, the executable modules comprise one or more algorithm(s)310 stored in memory that when executed causes the processor 308 togenerate an electrical signal output waveform comprising current (I),voltage (V), and/or frequency (f) for various time intervals or periods(T). The stepwise waveforms of the drive signals may be generated byforming a piecewise linear combination of constant functions over two ormore time intervals created by stepping the output drive current (I),voltage (V), and/or frequency (f) of the generator 300. The drivesignals may be generated either for predetermined fixed time intervalsor periods (T) of time or variable time intervals or periods of time inaccordance with the one or more algorithm(s) 310. Under control of theprocessor 308, the generator 100 outputs (e.g., increases or decreases)the current (I), voltage (V), and/or frequency (f) up or down at aparticular resolution for a predetermined period (T) or until apredetermined condition is detected, such as a change in a monitoredcharacteristic (e.g., transducer impedance, tissue impedance). The stepscan change in programmed increments or decrements. If other steps aredesired, the generator 300 can increase or decrease the step adaptivelybased on measured system characteristics.

In operation, the user can program the operation of the generator 300using the input device 312 located on the front panel of the generator300 console. The input device 312 may comprise any suitable device thatgenerates signals 314 that can be applied to the processor 308 tocontrol the operation of the generator 300. In various forms, the inputdevice 312 includes buttons, switches, thumbwheels, keyboard, keypad,touch screen monitor, pointing device, remote connection to a generalpurpose or dedicated computer. In other forms, the input device 312 maycomprise a suitable user interface. Accordingly, by way of the inputdevice 312, the user can set or program the current (I), voltage (V),frequency (f), and/or period (T) for programming the output of thegenerator 300. The processor 308 then displays the selected power levelby sending a signal on line 316 to an output indicator 318.

In various forms, the output indicator 318 may provide visual, audible,and/or tactile feedback to the surgeon to indicate the status of asurgical procedure, such as, for example, when tissue cutting andcoagulating is complete based on a measured characteristic of theultrasonic surgical instrument 104, e.g., transducer impedance, tissueimpedance, or other measurements as subsequently described. By way ofexample, and not limitation, visual feedback comprises any type ofvisual indication device including incandescent lamps or LEDs, graphicaluser interface, display, analog indicator, digital indicator, bar graphdisplay, digital alphanumeric display. By way of example, and notlimitation, audible feedback comprises any type of buzzer, computergenerated tone, computerized speech, voice user interface (VUI) tointeract with computers through a voice/speech platform. By way ofexample, and not limitation, tactile feedback comprises any type ofvibratory feedback provided through an instrument housing handleassembly.

In one form, the processor 308 may be configured or programmed togenerate a digital current signal 320 and a digital frequency signal322. These digital signals 320, 322 are applied to a digital synthesiscircuit such as the DDS circuit 324 (see e.g., FIGS. 13, 14) to adjustthe amplitude and the frequency (f) of the ultrasonic electrical drivesignal 304 to the transducer. The output of the DDS circuit 324 isapplied to a power amplifier 326 whose output is applied to atransformer 328. The output of the transformer 328 is the ultrasonicelectrical drive signal 304 applied to the ultrasonic transducer 306,which is coupled to a blade by way of a waveguide. The output of the DDScircuit 324 may be stored in one more memory circuits including volatile(RAM) and non-volatile (ROM) memory circuits.

In one form, the generator 300 comprises one or more measurement modulesor components that may be configured to monitor measurablecharacteristics of the ultrasonic instrument 104 (FIGS. 1, 2) or themultifunction surgical instrument 108 (FIGS. 1-3). In the illustratedform, the processor 308 may be employed to monitor and calculate systemcharacteristics. As shown, the processor 308 measures the impedance Z ofthe transducer by monitoring the current supplied to the ultrasonictransducer 306 and the voltage applied to the transducer. In one form, acurrent sense circuit 330 is employed to sense the current flowingthrough the transducer and a voltage sense circuit 332 is employed tosense the output voltage applied to the ultrasonic transducer 306. Thesesignals may be applied to the ADC circuit 336 via an analog multiplexer334 circuit or switching circuit arrangement. The analog multiplexer 334routes the appropriate analog signal to the ADC circuit 336 forconversion. In other forms, multiple ADC circuits 336 may be employedfor each measured characteristic instead of the analog multiplexer 334circuit. The processor 308 receives the digital output 338 of the ADCcircuit 336 and calculates the transducer impedance Z based on themeasured values of current and voltage. The processor 308 adjusts theultrasonic electrical drive signal 304 such that it can generate adesired power versus load curve. In accordance with programmedalgorithm(s) 310, the processor 308 can step the ultrasonic electricaldrive signal 304, e.g., the current or frequency, in any suitableincrement or decrement in response to the transducer impedance Z.

FIG. 7 illustrates one aspect of a drive system 402 of the generator400, which is one form of the generator 100 (FIGS. 1-3). In operation,the user can program the operation of the generator 400 using the inputdevice 412 located on the front panel of the generator 400 console. Theinput device 412 may comprise any suitable device that generates signals414 that can be applied to the processor 408 to control the operation ofthe generator 400. In various forms, the input device 412 includesbuttons, switches, thumbwheels, keyboard, keypad, touch screen monitor,pointing device, remote connection to a general purpose or dedicatedcomputer. In other forms, the input device 412 may comprise a suitableuser interface. Accordingly, by way of the input device 412, the usercan set or program the current (I), voltage (V), frequency (f), and/orperiod (T) for programming the output of the generator 400. Theprocessor 408 then displays the selected power level by sending a signalon line 416 to an output indicator 418.

The generator 400 comprises a tissue impedance module 442. The drivesystem 402 is configured to generate electrical drive signal 404 todrive the ultrasonic transducer 406. In one aspect, the tissue impedancemodule 442 may be configured to measure the impedance Zt of tissuegrasped between the blade 440 and the clamp arm assembly 444. The tissueimpedance module 442 comprises an RF oscillator 446, an RF voltagesensing circuit 448, and an RF current sensing circuit 450. The RFvoltage and RF current sensing circuits 448, 450 respond to the RFvoltage Vrf applied to the blade 440 electrode and the RF current irfflowing through the blade 440 electrode, the tissue, and the conductiveportion of the clamp arm assembly 444. The sensed voltage Vrf andcurrent Irf are converted to digital form by the ADC circuit 436 via theanalog multiplexer 434. The processor 408 receives the digital output438 of the ADC circuit 436 and determines the tissue impedance Zt bycalculating the ratio of the RF voltage Vrf to current Irf measured bythe RF voltage sense circuit 448 and the RF current sense circuit 450.In one aspect, the transection of the inner muscle layer and the tissuemay be detected by sensing the tissue impedance Zt. Accordingly,detection of the tissue impedance Zt may be integrated with an automatedprocess for separating the inner muscle layer from the outer adventitialayer prior to transecting the tissue without causing a significantamount of heating, which normally occurs at resonance.

In one form, the RF voltage Vrf applied to the blade 440 electrode andthe RF current Irf flowing through the blade 440 electrode, the tissue,and the conductive portion of the clamp arm assembly 451 are suitablefor vessel sealing and/or dissecting. Thus, the RF power output of thegenerator 400 can be selected for non-therapeutic functions such astissue impedance measurements as well as therapeutic functions such asvessel sealing and/or dissection. It will be appreciated, that in thecontext of the present disclosure, the ultrasonic and the RFelectrosurgical energies can be supplied by the generator eitherindividually or simultaneously.

In various forms, feedback is provided by the output indicator 418 shownin FIGS. 6 and 7. The output indicator 418 is particularly useful inapplications where the tissue being manipulated by the end effector isout of the user's field of view and the user cannot see when a change ofstate occurs in the tissue. The output indicator 418 communicates to theuser that a change in tissue state has occurred. As previouslydiscussed, the output indicator 418 may be configured to provide varioustypes of feedback to the user including, without limitation, visual,audible, and/or tactile feedback to indicate to the user (e.g., surgeon,clinician) that the tissue has undergone a change of state or conditionof the tissue. By way of example, and not limitation, as previouslydiscussed, visual feedback comprises any type of visual indicationdevice including incandescent lamps or LEDs, graphical user interface,display, analog indicator, digital indicator, bar graph display, digitalalphanumeric display. By way of example, and not limitation, audiblefeedback comprises any type of buzzer, computer generated tone,computerized speech, VUI to interact with computers through avoice/speech platform. By way of example, and not limitation, tactilefeedback comprises any type of vibratory feedback provided through theinstrument housing handle assembly. The change of state of the tissuemay be determined based on transducer and tissue impedance measurementsas previously described, or based on voltage, current, and frequencymeasurements.

In one form, the processor 408 may be configured or programmed togenerate a digital current signal 420 and a digital frequency signal422. These digital signals 420, 422 are applied to a digital synthesiscircuit such as the DDS circuit 424 (see e.g., FIGS. 13, 14) to adjustthe amplitude and the frequency (f) of the electrical drive signal 404to the ultrasonic transducer 406. The output of the DDS circuit 424 isapplied to a power amplifier 426 whose output is applied to atransformer 428. The output of the transformer 428 is the electricaldrive signal 404 applied to the ultrasonic transducer 406, which iscoupled to a blade by way of a waveguide. The output of the DDS circuit424 may be stored in one more memory circuits including volatile (RAM)and non-volatile (ROM) memory circuits.

In one form, the generator 400 comprises one or more measurement modulesor components that may be configured to monitor measurablecharacteristics of the ultrasonic instrument 104 (FIGS. 1, 3) or themultifunction electrosurgical/ultrasonic instrument 108 (FIGS. 1-3). Inthe illustrated form, the processor 408 may be employed to monitor andcalculate system characteristics. As shown, the processor 408 measuresthe impedance Z of the transducer by monitoring the current supplied tothe ultrasonic transducer 406 and the voltage applied to the transducer.In one form, a current sense circuit 430 is employed to sense thecurrent flowing through the transducer and a voltage sense circuit 432is employed to sense the output voltage applied to the ultrasonictransducer 406. These signals may be applied to the ADC circuit 436 viaan analog multiplexer 434 circuit or switching circuit arrangement. Theanalog multiplexer 434 routes the appropriate analog signal to the ADCcircuit 436 for conversion. In other forms, multiple ADC circuits 436may be employed for each measured characteristic instead of the analogmultiplexer 434 circuit. The processor 408 receives the digital output438 of the ADC circuit 436 and calculates the transducer impedance Zbased on the measured values of current and voltage. The processor 308adjusts the electrical drive signal 404 such that it can generate adesired power versus load curve. In accordance with programmedalgorithm(s) 410, the processor 408 can step the ultrasonic electricaldrive signal 404, e.g., the current or frequency, in any suitableincrement or decrement in response to the transducer impedance Z.

With reference to FIGS. 6 and 7, in various forms, the variousexecutable instructions or modules (e.g., algorithms 310, 410)comprising computer readable instructions can be executed by theprocessor 308, 408 portion of the generator 300, 400. In various forms,the operations described with respect to the algorithms may beimplemented as one or more software components, e.g., programs,subroutines, logic; one or more hardware components, e.g., processors,DSPs, PLDs, ASICs, circuits, registers; and/or combinations of softwareand hardware. In one form, the executable instructions to perform thealgorithms may be stored in memory. When executed, the instructionscause the processor 308, 408 to determine a change in tissue stateprovide feedback to the user by way of the output indicator 318, 418. Inaccordance with such executable instructions, the processor 308, 408monitors and evaluates the voltage, current, and/or frequency signalsamples available from the generator 300, 400 and according to theevaluation of such signal samples determines whether a change in tissuestate has occurred. As further described below, a change in tissue statemay be determined based on the type of ultrasonic instrument and thepower level that the instrument is energized at. In response to thefeedback, the operational mode of the surgical instruments 104, 106, 108(FIGS. 1-3) may be controlled by the user or may be automatically orsemi-automatically controlled.

FIG. 8 illustrates an example of a generator 500, which is one form ofthe generator 100 (FIGS. 1-3). The generator 500 is configured todeliver multiple energy modalities to a surgical instrument. Thegenerator 500 includes functionalities of the generators 200, 300, 400shown in FIGS. 5-7. The generator 500 provides RF and ultrasonic signalsfor delivering energy to a surgical instrument. The RF and ultrasonicsignals may be provided alone or in combination and may be providedsimultaneously. As noted above, at least one generator output candeliver multiple energy modalities (e.g., ultrasonic, bipolar ormonopolar RF, irreversible and/or reversible electroporation, and/ormicrowave energy, among others) through a single port and these signalscan be delivered separately or simultaneously to the end effector totreat tissue. The generator 500 comprises a processor 502 coupled to awaveform generator 504. The processor 502 and waveform generator 504 areconfigured to generate a variety of signal waveforms based oninformation stored in a memory coupled to the processor 502, not shownfor clarity of disclosure. The digital information associated with awaveform is provided to the waveform generator 504 which includes one ormore DAC circuits to convert the digital input into an analog output.The analog output is fed to an amplifier 1106 for signal conditioningand amplification. The conditioned and amplified output of the amplifier506 is coupled to a power transformer 508. The signals are coupledacross the power transformer 508 to the secondary side, which is in thepatient isolation side. A first signal of a first energy modality isprovided to the surgical instrument between the terminals labeledENERGY1 and RETURN. A second signal of a second energy modality iscoupled across a capacitor 510 and is provided to the surgicalinstrument between the terminals labeled ENERGY2 and RETURN. It will beappreciated that more than two energy modalities may be output and thusthe subscript “n” may be used to designate that up to n ENERGYnterminals may be provided, where n is a positive integer greater than 1.It also will be appreciated that up to “n” return paths RETURNn may beprovided without departing from the scope of the present disclosure.

A first voltage sensing circuit 512 is coupled across the terminalslabeled ENERGY1 and the RETURN path to measure the output voltagetherebetween. A second voltage sensing circuit 524 is coupled across theterminals labeled ENERGY2 and the RETURN path to measure the outputvoltage therebetween. A current sensing circuit 514 is disposed inseries with the RETURN leg of the secondary side of the powertransformer 508 as shown to measure the output current for either energymodality. If different return paths are provided for each energymodality, then a separate current sensing circuit should be provided ineach return leg. The outputs of the first and second voltage sensingcircuits 512, 524 are provided to respective isolation transformers 516,522 and the output of the current sensing circuit 514 is provided toanother isolation transformer 518. The outputs of the isolationtransformers 516, 518, 522 in the on the primary side of the powertransformer 508 (non-patient-isolated side) are provided to a one ormore ADC circuit 526. The digitized output of the ADC circuit 526 isprovided to the processor 502 for further processing and computation.The output voltages and output current feedback information can beemployed to adjust the output voltage and current provided to thesurgical instrument and to compute output impedance, among otherparameters. Input/output communications between the processor 502 andpatient isolated circuits is provided through an interface circuit 520.Sensors also may be in electrical communication with the processor 502by way of the interface circuit 520.

In one aspect, the impedance may be determined by the processor 502 bydividing the output of either the first voltage sensing circuit 512coupled across the terminals labeled ENERGY1/RETURN or the secondvoltage sensing circuit 524 coupled across the terminals labeledENERGY2/RETURN by the output of the current sensing circuit 514 disposedin series with the RETURN leg of the secondary side of the powertransformer 508. The outputs of the first and second voltage sensingcircuits 512, 524 are provided to separate isolations transformers 516,522 and the output of the current sensing circuit 514 is provided toanother isolation transformer 516. The digitized voltage and currentsensing measurements from the ADC circuit 526 are provided the processor502 for computing impedance. As an example, the first energy modalityENERGY1 may be ultrasonic energy and the second energy modality ENERGY2may be RF energy. Nevertheless, in addition to ultrasonic and bipolar ormonopolar RF energy modalities, other energy modalities includeirreversible and/or reversible electroporation and/or microwave energy,among others. Also, although the example illustrated in FIG. 8 shows asingle return path RETURN may be provided for two or more energymodalities, in other aspects multiple return paths RETURNn may beprovided for each energy modality ENERGYn. Thus, as described herein,the ultrasonic transducer impedance may be measured by dividing theoutput of the first voltage sensing circuit 512 by the current sensingcircuit 514 and the tissue impedance may be measured by dividing theoutput of the second voltage sensing circuit 524 by the current sensingcircuit 514.

As shown in FIG. 8, the generator 500 comprising at least one outputport can include a power transformer 508 with a single output and withmultiple taps to provide power in the form of one or more energymodalities, such as ultrasonic, bipolar or monopolar RF, irreversibleand/or reversible electroporation, and/or microwave energy, amongothers, for example, to the end effector depending on the type oftreatment of tissue being performed. For example, the generator 500 candeliver energy with higher voltage and lower current to drive anultrasonic transducer, with lower voltage and higher current to drive RFelectrodes for sealing tissue, or with a coagulation waveform for spotcoagulation using either monopolar or bipolar RF electrosurgicalelectrodes. The output waveform from the generator 500 can be steered,switched, or filtered to provide the frequency to the end effector ofthe surgical instrument. The connection of an ultrasonic transducer tothe generator 500 output would be preferably located between the outputlabeled ENERGY1 and RETURN as shown in FIG. 8. An In one example, aconnection of RF bipolar electrodes to the generator 500 output would bepreferably located between the output labeled ENERGY2 and RETURN. In thecase of monopolar output, the preferred connections would be activeelectrode (e.g., pencil or other probe) to the ENERGY2 output and asuitable return pad connected to the RETURN output.

In other aspects, the generators 100, 200, 300, 400, 500 described inconnection with FIGS. 1-3 and 5-8, the ultrasonic drive circuit 114,and/or electrosurgery/RF drive circuit 116 as described in connectionwith FIG. 3 may be formed integrally with any one of the surgicalinstruments 104, 106, 108 described in connection with FIGS. 1 and 2.Accordingly, any of the processors, digital signal processors, circuits,controllers, logic devices, ADCs, DACs, amplifiers, converters,transformers, signal conditioners, data interface circuits, current andvoltage sensing circuits, direct digital synthesis circuits, multiplexer(analog or digital), waveform generators, RF generators, memory, and thelike, described in connection with any one of the generators 100, 200,300, 400, 500 can be located within the surgical instruments 104, 106,108 or may be located remotely from the surgical instruments 104, 106,108 and coupled to the surgical instruments via wired and/or wirelesselectrical connections.

FIG. 9 shows a diagram of an electrosurgical system 9000 that allows fortwo ports on a generator 9001 and accounts for electrical isolationbetween two surgical instruments 9007, 9008. A scheme is provided forelectrical isolation between the two instruments 9007, 9008 as they arelocated on the same patient isolation circuit. According to theconfiguration shown in FIG. 9, unintended electrical power feedback isprevented through the electrosurgical system 9000. In various aspects,power field effect transistors (FETs) or relays are used to electricallyisolate all power lines for each of the two surgical instrument 9007,9008. According to one aspect, the power FETs or relays are controlledby a 1-wire communication protocol.

As shown in FIG. 9, a generator 9001, which is one form of the generator100 (FIGS. 1-3), is coupled to a power switching mechanism 9003 and acommunications system 9005. In one aspect, the power switching mechanism9003 comprises power solid state switches such as, for example, FET ormetal oxide semiconductor FET (MOSFET) transistors, and/or relays, suchas electromechanical relays. In one aspect, the communications system9005 comprises components for D1 emulation, FPGA expansion, and timeslicing functionalities. The power switching mechanism 9003 is coupledto the communications system 9005. Each of the power switching mechanism9003 and the communications system 9005 are coupled to surgicalinstruments 9007, 9009 (labeled device 1 and device 2). Each of surgicalinstruments 9007, 9009 comprise components for a combined RF andultrasonic energy input 9011, handswitch (HSW) 1-wire serial protocolinterface 9013, HP 1-wire protocol interface 9015, and a presenceinterface 9017. The power switching mechanism 9003 is coupled to the RFand ultrasonic energy input 9011 for each of surgical instruments 9007,9008. The communications system 9005 is coupled to the HSW 1-wire serialinterface 9013, 9014, the HP 1-wire serial protocol interface 9015,9016, and presence interface 9017, 9018 for each of surgical instruments9007, 9008. While two surgical instruments are shown in FIG. 9, theremay be more than two devices according to various aspects.

FIGS. 10-12 illustrate aspects of an interface with a generator tosupport two instruments simultaneously that allows the instruments toquickly switch between active/inactive by a user in a sterile field.FIGS. 10-12 describe multiple communication schemes which would allowfor a super cap/battery charger and dual surgical instruments. Theaspects of FIGS. 10-12 allow for communications to two surgicalinstruments in the surgical field from a generator with at least onecommunications port and allow for an operator in sterile field to switchbetween devices, for example, without modifying the surgicalinstruments.

FIG. 10 is a diagram of a communications architecture of system 1001comprising a generator 1003, which is one form of the generator 100(FIGS. 1-3), and surgical instruments 9007, 9008, which are shown inFIG. 9. According to FIG. 10, the generator 9001 is configured fordelivering multiple energy modalities to a plurality of surgicalinstruments. As discussed herein the various energy modalities include,without limitation, ultrasonic, bipolar or monopolar RF, reversibleand/or irreversible electroporation, and/or microwave energy modalities.The generator 9001 comprises a combined energy modality power output1005, a communications interface 1007, and a presence interface 1049.According to the aspect of FIG. 10, the communications interface 1007comprises an handswitch (HSW) serial interface 1011 and an handpiece(HP) serial interface 1013. The serial interfaces 1011, 1013 maycomprise inter-integrated circuit (I²C), half duplex SPI, and/orUniversal Asynchronous Receiver Transmitter (UART) components and/orfunctionalities. The generator 1003 provides the combined energymodalities power output 1005 to an adapter 1015, for example, apass-through charger (PTC). The adapter 1015 comprises energy storagecircuit 1071, control circuit 1019, a unique presence element 1021, andassociated circuit discussed below. In one aspect, the presence element1021 is a resistor. In another aspect, the presence element 1021 may bea bar code, Quick Response (QR) code, or similar code, or a value storedin memory such as, for example, a value stored in NVM. The presenceelement 1021 may be unique to the adapter 1015 so that, in the eventthat another adapter that did not use the same wire interfaces could notbe used with the unique presence element 1021. In one aspect, the uniquepresence element 1021 is a resistor. The energy storage circuit 1071comprises a switching mechanism 1023, energy storage device 1025,storage control 1027, storage monitoring component 1029, and a devicepower monitoring component 1031. The control circuit 1019 may comprise aprocessor, FPGA, PLD, complex programmable logic device (CPLD),microcontroller, DSP, and/or ASIC, for example. According to the aspectshown in FIG. 10, an FPGA or microcontroller would act as an extensionof an existing, similar computing hardware and allows for information tobe relayed from on entity to another entity.

The switching mechanism 1023 is configured to receive the combinedenergy power output 1005 from the generator 1003 and it may be providedto the energy storage device 1025, surgical instrument 9007, and/orsurgical instrument 9008. The device power monitoring component 1031 iscoupled to the channels for the energy storage device 1025, surgicalinstrument 9007, surgical instrument 9008, and may monitor where poweris flowing. The control circuit 1019 comprises communication interface1033 coupled to the handswitch serial interface 1011 and an handpieceserial interface 1013 of the generator 1003. The control circuit 1019 isalso coupled to the storage control 1027, storage monitoring component1029, and device power monitoring component 1031 of the energy storagecircuit 1071.

The control circuit 1019 further comprises a serial master interface1035 that is coupled to handswitch (HSW) #1 circuit 1037 and handswitch(HSW) #2 circuit 1038, includes generation and ADC, a form of memory(non volatile or flash) 1039, along with a method for detecting thepresence of an attached instrument (Presence) #1 circuit 1041 andPresence #2 circuit 1042, which includes a voltage or current source andADC. The serial master interface 1035 also includes handswitch NVMbypass channels, which couple the serial master interface 1035 to theoutputs of the handswitch #1 circuit 1037 and the handswitch #2 circuit1038, respectively. The handswitch #1 circuit 1037 and handswitch #2circuit 1038 are coupled to the HSW 1-wire serial protocol interfaces9013, 9014 of the surgical instruments 9007, 9008, respectively. Theserial master interface 1035 further includes handpiece serial channelsthat are coupled to the HP 1-wire serial protocol interfaces 9015, 9016of the surgical instruments 9007, 9008, respectively. Further, Presence#1 and Presence #2 circuits 1041, 1042 are coupled to the presenceinterfaces 9017, 9018 of the surgical instruments 9007, 9008,respectively.

The system 1001 allows the control circuit 1019, such as an FPGA, tocommunicate with more surgical instruments using adapter 1015, whichacts as an expansion adapter device. According to various aspects, theadapter 1015 expands the Input/Output (I/O) capability of the generator1003 control. The adapter 1015 may function as an extension of thecentral processing unit that allows commands to be transmitted over abus between the adapter 1015 and the generator 1003 and unpacks thecommands and use them to bit-bang over interfaces or to controlconnected analog circuit. The adapter 1015 also allows for reading inADC values from connected surgical instruments 9007, 9008 and relay thisinformation to the generator control and the generator control wouldthen control the two surgical instruments 9007, 9008. According tovarious aspects, the generator 1003 may control the surgical instruments9007, 9008 as two separate state machines and may store the data.

Existing interfaces (the handswitch serial interface 1011 and thehandpiece serial interface 1013 lines from generator 1003) may be usedin a two-wire communication protocol that enables the generator 1003control to communicate with multiple surgical instruments connected to adual port interface, similar to the topology of a universal serial bus(USB) hub.

This allows interfacing with two separate surgical instrumentssimultaneously. The system 1001 may be able to generate and read handswitch waveforms and be able to handle incoming handpiece serial buses.It would also monitor two separate presence elements in the surgicalinstruments 9007, 9008. In one aspect, the system 1001 may include aunique presence element and may have its own NVM.

Further, according to various aspects, the control circuit 1019 may becontrolled by the generator 1003. The communication between the adapter1015 and connected surgical instruments 9007, 9008 may be relayed togenerator control. The generator 1003 would control the waveformgeneration circuit connected to the adapter 1015 to simultaneouslygenerate handswitch signals for surgical instruments 9007, 9008.

The system 1001 may allow surgical instrument activity that can besimultaneously detected/monitored for two surgical instruments, evenduring activation. If upgradeable, the adapter 1015 would be capable ofhandling new surgical instrument communications protocols. Further, fastswitching between surgical instruments may be accomplished.

FIG. 11 illustrates a communication architecture of system 1101 of agenerator 1103, which is one form of the generator 100 (FIGS. 1-3), andsurgical instruments 9007, 9008 shown in FIG. 9. According to FIG. 11,the generator 1103 is configured for delivering multiple energymodalities to a plurality of surgical instruments. As discussed hereinthe various energy modalities include, without limitation, ultrasonic,bipolar or monopolar RF, reversible and/or irreversible electroporation,and/or microwave energy modalities. As shown in FIG. 11, the generator1103 comprises a combined energy modality power output 1105, anhandswitch (HSW) serial interface 1111, a handpiece (HP) serialinterface 1113, and a presence interface 1109. The generator 1103provides the power output 1105 to an adapter 1115. According to theaspect shown in FIG. 11, communications between the adapter 1115 and thegenerator 1103 may be done solely through serial interfaces, such as thehandswitch serial and handpiece serial interfaces 1111, 1113. Thegenerator 1103 may use these handswitch and handpiece serial interfaces1111, 1113 to control which instrument the generator 1103 iscommunicating with. Further, switching between instruments could occurbetween handswitch frames or at a much slower rate.

The adapter 1115 comprises an energy storage circuit 1117, a controlcircuit 1119, an adapter memory 1121 (e.g., a NVM such as an EEPROM), aserial programmable input/output (PIO) integrated circuit 1133, anhandswitch Switching Mechanism 1135, an handpiece Switching Mechanism1137, a Presence Switching Mechanism 1139, and a Generic Adapter 1141.In one aspect, the serial PIO integrated circuit 1133 may be anaddressable switch. The energy storage circuitry 1117 comprises aswitching mechanism 1123, energy storage device 1125, storage controlcomponent 1127, storage monitoring component 1129, and a device powermonitoring component 1131. The control circuit 1119 may comprise aprocessor, FPGA, CPLD, PLD, microcontroller, DSP, and/or an ASIC, forexample. According to the aspect of FIG. 11, an FPGA or microcontrollermay have limited functionality and may solely comprise functionality formonitoring and communicating energy storage.

The switching mechanism 1123 is configured to receive the combinedenergy power output 1105 from the generator 1103 and it may be providedto the energy storage device 1125, surgical instrument 9007, and/orsurgical instrument 9008. The device power monitoring component 1131 iscoupled to the channels for the energy storage device 1125, surgicalinstrument 9007, surgical instrument 9008, and may monitor where poweris flowing.

The control circuit 1119 is coupled to the serial PIO integrated circuit1133 and the serial PIO integrated circuit 1133 is coupled to thehandpiece serial interface 1113 of the generator 1103. The controlcircuit 1119 may receive information regarding charger status flags andswitching controls from the serial PIO integrated circuit 1133. Further,the control circuit 1119 is coupled to the handswitch switchingmechanism 1135, the handpiece switching mechanism 1137, and the presenceswitching mechanism 1139. According to the aspect of FIG. 11, thecontrol circuit 1119 may be coupled to the handswitch (HSW) switchingmechanism 1135 and the handpiece switching mechanism 1137 for deviceselection and the control circuit 1119 may be coupled to the presenceswitching Mechanism 1139 for presence selection.

The handswitch switching mechanism 1135, the handpiece switchingmechanism 1137, and the presence switching mechanism 1139 are coupled tothe handswitch serial interface 1111, the handpiece serial interface1113, and the presence interface 1109 of generator 1103, respectively.Further, the handswitch switching mechanism 1135, the handpieceswitching mechanism 1137, and the presence switching mechanism 1139 arecoupled to the HSW 1-wire serial protocol interfaces 9013, 9014, the HP1-wire serial protocol interfaces 9015, 9016, and the presenceinterfaces 9017, 9018 of the surgical instruments 9007, 9008,respectively. Further, the presence switching mechanism 1139 is coupledto the generic adapter 1141.

The generator 1103 switches between monitoring the surgical instruments9007, 9008. According to various aspects, this switching may require thegenerator 1103 control to keep track of surgical instruments 9007, 9008and run two separate state machines. The control circuit 1119 will needto remember which surgical instruments are connected, so that it canoutput an appropriate waveform to the ports where appropriate. Thegenerator 1103 may generate/monitor hand switch signals, as well ascommunicating with serial NVM devices, such adapter memory 1121. Thegenerator 1103 may maintain constant communication with the activatingsurgical instrument for the duration of the activation.

System 1101 also allows for a generic adapter presence element. Whenfirst plugged in or powered on, the adapter 1115 would present thisadapter resistance to the generator 1103. The generator 1103 may thenrelay commands to the adapter 1115 to switch between the differentpresence elements corresponding to the different surgical instruments9007, 9008 connected to it. Accordingly, the generator 1103 is able touse its existing presence resistance circuit. The NVM adapter memory1121 exists on the adapter 1115 for additional identification of theadapter and to provide a level of security. In addition, the adapter1115 has a serial I/O device, i.e. serial PIO integrated circuit 1133.The serial PIO integrated circuit 1133 provides a communication linkbetween the generator 1103 and the adapter 1115.

It may be possible to communicate over the handpiece serial bus usingserial communications to handpiece NVMs and UART style communication tothe control circuit 1119. According to one aspect, if SLOW serialcommunication is used (i.e. not overdrive) and a high speed serialprotocol is used, system 1101 may need to ensure that the communicationsprotocol does not generate a signal that looked like a serial resetpulse. This would allow better generator 1103 to adapter 1115communications and faster switching times between surgical instruments9007, 9008.

The system 1101 uses generator communications protocol and analogcircuit and allows the generator to accomplish decision making. It is asimple and efficient solution that uses a small number of circuitdevices.

FIG. 12 illustrates a communications architecture of system 1201 of agenerator 1203, which is one form of the generator 100 (FIGS. 1-3), andsurgical instruments 9007, 9008 shown in FIG. 9. According to FIG. 12,the generator 1203 is configured for delivering multiple energymodalities to a plurality of surgical instruments. As discussed hereinthe various energy modalities include, without limitation, ultrasonic,bipolar or monopolar RF, reversible and/or irreversible electroporation,and/or microwave energy modalities. As shown in FIG. 12, the generator1203 comprises a combined energy modality power output 1205, anhandswitch serial interface 1211, an handpiece serial interface 1213,and a presence interface 1209. In one aspect, the handpiece serialinterface 1213 allows for communication with the handpiece lines of thesurgical instruments 9007, 9008 and also allows for control of theadapter 1215. The generator 1203 provides the combined energy modalitypower output 1205 to an adapter 1215. The adapter 1215 comprises energystorage circuit 1217, control circuit 1219, a serial PIO integratedcircuit 1233, handswitch (HSW) #1 circuit 1231, handswitch (HSW) #2circuit 1271, handpiece switching mechanism 1221, presence switchingmechanism 1239, switching mechanism 1235, instrument power monitoring1237, and unique presence 1241. As shown in FIG. 12, the handswitch #1circuit 1231 and the handswitch #2 circuit 1271 may comprise generationand ADC circuits. In one aspect, handswitch #1 circuit 1231 and/orhandswitch #2 circuit 1271 comprise generation circuit with the abilityto generate handswitch waveforms.

The control circuit 1219 is coupled to the handswitch serial interface1211 of the generator 1203 while the serial PIO integrated circuit 1233is coupled to the handpiece serial interface 1213 as is the handpieceswitching mechanism 1221. Further, the control circuit 1119 is coupledto the handswitch #1 circuit 1231 and the handswitch #2 circuit 1271.The control circuit 1119 may comprise a processor, FPGA, CPLD, PLD,microcontroller, and/or ASIC, for example. In the example shown in FIG.12, the control circuit 1219 modulates two devices into at least onedigital waveform, which enable the generator 1203 to perform the buttonmonitoring and decision making. The control circuit 1219 also may allowfor communication to two independent surgical instruments could receiveeither waveform. The serial PIO integrated circuit 1233 is furthercoupled to the handpiece switching mechanism 1221, the instrument powermonitoring 1237, and the presence switching mechanism 1239. Theinstrument power monitoring 1237 and the serial PIO integrated circuit1233 may communicate results and failures to the generator 1203.

The switching mechanism 1223 is configured to receive the combinedRF/ultrasonic power output 1205 from the generator 1203 and it may beprovided to the energy storage circuit 1225 or the switching mechanism1235. The control circuit 1219 is also coupled to the storage control1227 and storage monitoring 1229 of the energy storage circuit 1217. Theswitching mechanism 1235 may provide the power output received from theswitching mechanism 1223 to surgical instrument 9007, and/or surgicalinstrument 9008. The instrument power monitoring 1237 is coupled to thechannels for the power output to the surgical instrument 9007 andsurgical instrument 9008. The instrument power monitoring 1237 also mayensure that the switching mechanism 1235 is outputting power to correctlocation.

The handswitch #1 circuit 1231 and the handswitch #2 circuit 1271 arecoupled to the HSW 1-wire serial protocol interfaces 9013, 9014 of thesurgical instruments 9007, 9008, respectively. The handpiece switchingmechanism 1221 is coupled to the handpiece serial interface 1213 of thegenerator 1203 and to the HP 1-wire serial protocol interfaces 9015,9016 of the surgical instruments 9007, 9008, respectively. Further, thepresence switching mechanism 1239 is coupled to the presence interface1209 of the generator 1203 and to the presence interfaces 9017, 9018 ofthe surgical instruments 9007, 9008, respectively. Further, PresenceSwitching mechanism is coupled to the unique presence 1241. In oneaspect, different instrument presence elements may be switched on anon-demand basis using serial I/O or an adapter micro protocol.

A first communications protocol will be used to communicate to thecontrol circuit 1219 on the adapter 1215. The generator 1203 also mayhave the ability to monitor surgical instruments 9007, 9008 at once. Theadapter 1215 may comprise circuit to provide handswitch signalgeneration (e.g., in handswitch #1 circuit 1231 and handswitch #2circuit 1271) along with ADCs to interpret this data. The adapter 1215may modulate two surgical instrument signals into at least a firstwaveform and may have the ability to read in the first and secondwaveforms. In various aspects, the second waveforms may be interpretedand translated into the format of the first waveforms. Further, thefirst protocol has the ability to send 12 bits at 615 bits/sec.

The control circuit 1219 may take the handswitch data from surgicalinstruments 9007, 9008 and modulate it into a first protocol. There area few ways of doing this, but it may mean that surgical instruments9007, 9008 may comprise a first protocol functionality. The system 1201could communicate 4-6 buttons from the surgical instrument 9007 and 4-6buttons from the surgical instrument 9008 in the first protocol frame.Alternatively, the system 1201 could use some form of addressing toaccess the surgical instruments 9007, 9008. The control circuit 1219 mayhave the ability to address separate devices by having the generator1203 send the control circuit 1219 different addresses split into twodifferent address spaces, one for surgical instrument 9007 and one forsurgical instrument 9008.

The handpiece communications may involve some form of switch that couldeither be controlled via a serial I/O device or through the controlcircuit 1219 via a first protocol style communication interface from thegenerator 1203. In one aspect, energy storage monitoring 1229 andswitching between surgical instruments 9007, 9008 and charging statescould be handled in this manner as well. Certain first protocoladdresses could be assigned to the data from the energy storage circuit1225 and to the surgical instruments 9007, 9008 themselves. Presenceelements could also be switched in with this format. Further, in oneaspect, the control circuit 1219 may translate frames into a separateformat, which may mean that the control circuit 1219 might need to makesome decisions on whether button presses on surgical instruments 9007,9008 are valid or not. The system 1201 would, however, allow thegenerator 1203 to fully monitor the surgical instruments 9007, 9008 atthe same time time-slicing or handling a new communications protocol onthe handswitch serial interface 1211 of the generator 1203. The system1201 uses generator communications to simultaneously detect the activityof two surgical instruments, even during activation.

As noted above, a single output generator can deliver both RF andultrasonic energy through a single port and these signals can bedelivered separately or simultaneously to the end effector to treattissue. One aspect of a combined RF and ultrasonic generator is shown inFIG. 1. As shown in FIG. 1, a single output port generator can include asingle output transformer with multiple taps to provide power, either RFor ultrasonic energy, to the end effector depending on the type oftreatment of tissue being performed. For example, the generator candeliver energy with higher voltage and lower current to drive anultrasonic transducer, with lower voltage and higher current as requiredto drive electrodes for sealing tissue, or with a coagulation waveformfor spot coagulation using either monopolar or bipolar electrosurgicalelectrodes. The output waveform from the generator can be steered,switched, or filtered to provide the desired frequency to the endeffector of the surgical instrument.

The surgical instruments described herein can also include features toallow the energy being delivered by the generator to be dynamicallychanged based on the type of tissue being treated by an end effector ofa surgical instrument. An algorithm for controlling the power outputfrom a generator, such as generator 1002, that is delivered to the endeffector of the surgical instrument can include an input that representsthe tissue type to allow the energy profile from the generator to bedynamically changed during the procedure based on the type of tissuebeing effected by the end effector of the surgical instrument.

Various algorithms can be used to select a power profile to allow theenergy being delivered from the generator to dynamically change based onthe tissue type being treated by the surgical instrument.

In order to determine the type of tissue being treated by the endeffector of the surgical instrument, a tissue coefficient of frictioncan be calculated. The calculated tissue coefficient of friction iscompared to a database of tissue coefficients of friction thatcorrelates each tissue coefficient with a tissue type, as will bediscussed in more detail below. The calculated tissue coefficient offriction and its related tissue type are used by an algorithm to controlthe energy being delivered from the generator to the surgicalinstrument. In one form, the tissue coefficient of friction is describedby:

$\mu = \frac{Q}{\vartheta \cdot N}$

Where Q is the rate of heat generation, θ is the velocity of theultrasonic motion of the end effector, and N is the force applied to thetissue by the end effector. The velocity of the ultrasonic motion is aknown value from the settings of the generator. Since the value θ is aknown value, the tissue coefficient of friction can be calculated usingthe slope of a graph of heat generation versus force on the tissue.

The force applied to the tissue by the end effector can be measured in avariety of ways using different type of components to measure force.This force measurement can be used, for example in the equation above,to determine the tissue coefficient of friction of the tissue beingtreated to determine its tissue type.

FIGS. 13-20 describe example systems that generate DC voltage in acircuit from a combined signal configured to supply both RF andultrasonic energy output to one or more surgical instruments.

FIG. 13 is a circuit diagram of a system 5300 that applies a band-stopfilter circuit design to generate a DC voltage within a surgicalinstrument. The DC voltage can be used to power components in thesurgical instrument. For example, the DC voltage could be used to drivea small motor for articulation of an end effector, or other uses asappropriate. As shown in FIG. 13 the system 5300 includes: theultrasonic and RF output of a generator 5301; and an instrument 5303including tuned band-stop filter circuits 5305, 5307 for each output ofthe generator 5301, a transducer model 5309 loaded to 400 ohms, and arectifier 5311 and motor load 5313 for the instrument 5303. In oneaspect, the rectifier 5311 produces 12V DC and the power consumed by themotor load 5313 is 5 W.

FIGS. 14-19 provide simulation results for the system 5300. For thesimulations, the ultrasonic output voltage was set to 150 Vrms and theRF voltage (350 kHz) is summed with the ultrasonic voltage that emulatesthe wave-shaping capability of a DDS within the generator. The RFcontent is initially off and then gated on at t=3 ms, in order to checkfor disturbances on the ultrasonic output. The RF amplitude was set to20V, which results in a rectified DC bus voltage of 12V_(DC). The motoris represented as a 30 ohm resistor that loads the DC bus toapproximately 5 W.

FIG. 14 displays the generator 5301 output at the ultrasonic terminaland the RF terminal in terms of voltage versus time. Plot 5401 is theultrasonic terminal voltage (measured at a reference of the capacitorlabeled Cf1) and Plot 5403 is the RF terminal voltage (measured at areference of the resistor labeled Rvs).

FIG. 15 displays the generator 5301 output from time 2.9 ms to 3.1 msfrom plots 5401 and 5403 in FIG. 14.

FIG. 16 is a circuit model 5309 of the ultrasonic transducer voltage andDC bus voltage provided by the rectifier 5311 in terms of voltage versustime. Plot 5601 is the transducer circuit model 5309 voltage (measuredat a reference of the resistor labeled Rp) and Plot 5603 is the DC busvoltage (measured at a reference of the diodes labeled D1 and D2).

FIG. 17 displays the transducer circuit model 5309 voltage and the DCbus voltage provided by the rectifier 5311 from time 2.9 ms to 3.1 ms asshown in plots 5601 and 5603 in FIG. 16.

FIG. 18 displays the power consumed by the load of the transducercircuit model 5309 and the power consumed by the motor load 5313 interms of watts versus time. Plot 5801 is the power consumed by the loadof the transducer circuit model 5309 (measured at a reference of theresistor labeled Rm) and Plot 5803 is the power consumed by the motorload 5313 (measured at a reference of the resistor labeled Rs1).

FIG. 19 displays the power consumed by the load of the transducercircuit model 5309 and the power consumed by the motor load 5313 fromtime 2.8 ms to 3.2 ms as shown in plots 5801 and 5803 in FIG. 18.

The simulations indicates that by using band-stop output filters, amixed frequency waveform produced by the generator can be split anddiverted to separate output loads. The simulation also shows that a DCbus can readily be generated to power a variety of low energy loadswithin the instrument 5303. According to the aspect of FIG. 13, there isnot an appreciable disturbance in the ultrasonic output when the DC busis active; however there are some distortions that can be seen as therectifier 5311 and capacitor (labeled Cf2) of filter circuit 5305 arecharging the DC bus. This distortion effect may be reduced bycontrolling the ramp rate of the high frequency content rather thanusing a step function.

FIG. 20 provides an illustration of a system configuration for anexample circuit topology shown and described with regard to FIGS. 13-19The system configuration comprises a plurality sections, where theplurality of sections include a generator (labeled GENERATOR), aproximal plug (labeled PLUG 1), a cable, a distal plug (labeled PLUG 2),a handle of a surgical instrument, and an application portion (labeledAPP) of a surgical instrument. According to various aspects, theproximal plug may be a component of the generator, it may be a componentof cable, or it may be separate component. Similarly, the distal plugmay be a component of the cable, it may be a component of handle, or itmay be separate component.

FIG. 20 further illustrates a system 7000 that includes bandstop filtersin the distal plug, an ASIC in the handle, and a DC motor in theapplication portion. The generator comprises interfaces for anultrasonic signal 7001, an interface for an RF signal 7003, a primaryreturn terminal interface 7005, an HSW interface 7007, a secondaryreturn terminal interface 7009, an identification interface 7011, and apresence interface 7013. The proximal plug comprises matching interfacesto those of generator, an EEPROM 7017, and presence resistor 7019. Theproximal plug outputs are carried through the cable without anycomponent circuitry in the cable. The distal plug comprises a pair ofbandstop filters 7015. The handle comprises rectifier circuit 7031, anon-volatile memory such as EEPROM 7035, control circuit 7027 (e.g.,ASIC), switch array 7037, capacitor 7016, and resonator 7029. Rectifiercircuit 7031 comprises at least one diode and at least one capacitor.Control circuit 7027 is coupled to EEPROM 7035, switch array 7037, andrectifier circuit 7031. The switch array 7037 may compriseelectro-mechanical devices such as transistor devices. The transistordevices may include Field-effect transistors (FET), Bipolar JunctionTransistors (BJT), or a combination thereof.

The application portion comprises EEPROM 7039, presence resistor 7041,and an output for ultrasonic energy 7045. The application portionfurther comprises rectifier circuit 7047, driver circuit 7049, drivercircuit 7051, and DC motor 7043. Rectifier circuit 7047 comprises atleast one diode and at least one capacitor. The rectifier circuit 7047is coupled to the driver circuit 7049, which is coupled to the DC motor7043. Driver circuit 7051 is coupled to control circuit 7027 and drivercircuit 7049. EEPROM 7039 and presence resistor 7041 are also coupled tocontrol circuit 7027. The system 7000 allows switching between an RFmode and an ultrasonic mode and supports mixed output frequencies, whichallows tissues impedance sensing while the ultrasonic output is active.It also provides for a DC motor at the ultrasonic output that usesenergy directed to the RF output terminal for generating a DC voltage.

Examples of waveforms representing energy for delivery from a generatorare illustrated in FIGS. 21-25. FIG. 21 illustrates an example graph 600showing first and second individual waveforms representing an RF outputsignal 602 and an ultrasonic output signal 604 superimposed on the sametime and voltage scale for comparison purposes. These output signals602, 604 are provided at the ENERGY output of the generator 100. Time(t) is shown along the horizontal axis and voltage (V) is shown alongthe vertical axis. The RF output signal 602 has a frequency of about 330kHz RF and a peak-to-peak voltage of ±1V. The ultrasonic output signal604 has a frequency of about 55 kHz and a peak-to-peak voltage of ±1V.It will be appreciated that the time (t) scale along the horizontal axisand the voltage (V) scale along the vertical axis are normalized forcomparison purposes and may be different actual implementations, orrepresent other electrical parameters such as current.

FIG. 22 illustrates an example graph 610 showing the sum of the twooutput signals 602, 604 shown in FIG. 21. Time (t) is shown along thehorizontal axis and voltage (V) is shown along the vertical axis. Thesum of the RF output signal 602 and the ultrasonic output signal 604shown in FIG. 21 produces a combined output signal 612 having a 2Vpeak-to-peak voltage, which is twice the amplitude of the original RFand ultrasonic signals shown (1V peak-to-peak) shown in FIG. 21. Anamplitude of twice the original amplitude can cause problems with theoutput section of the generator, such as distortion, saturation,clipping of the output, or stresses on the output components. Thus, themanagement of a single combined output signal 612 that has multipletreatment components is an important aspect of the generator 500 shownin FIG. 8. There are a variety of ways to achieve this management. Inone form, one of the two RF or ultrasonic output signals 602, 604 can bedependent on the peaks of the other output signal. In one aspect, the RFoutput signal 602 may depend on the peaks of the ultrasonic signal 604,such that the output is reduced when a peak is anticipated. Such afunction and resulting waveform is shown in FIG. 23.

For example, FIG. 23 illustrates an example graph 620 showing a combinedoutput signal 622 representative of a dependent sum of the outputsignals 602, 604 shown in FIG. 21. Time (t) is shown along thehorizontal axis and voltage (V) is shown along the vertical axis. Asshown in FIG. 21, the RF output signal 602 component of FIG. 21 dependson the peaks of the ultrasonic output signal 604 component of FIG. 21such that the amplitude of the RF output signal component of thedependent sum combined output signal 622 is reduced when an ultrasonicpeak is anticipated. As shown in the example graph 620 in FIG. 21, thepeaks have been reduced from 2 to 1.5. In another form, one of theoutput signals is a function of the other output signal.

For example, FIG. 24 illustrates an example graph of an analog waveform630 showing an output signal 632 representative of a dependent sum ofthe output signals 602, 604 shown in FIG. 21. Time (t) is shown alongthe horizontal axis and voltage (V) is shown along the vertical axis. Asshown in FIG. 24, the RF output signal 602 is a function of theultrasonic output signal 604. This provides a hard limit on theamplitude of the output. As shown in FIG. 24, the ultrasonic outputsignal 604 is extractable as a sine wave while the RF output signal 602has distortion but not in a way to affect the coagulation performance ofthe RF output signal 602.

A variety of other techniques can be used for compressing and/orlimiting the waveforms of the output signals. It should be noted thatthe integrity of the ultrasonic output signal 604 (FIG. 21) can be moreimportant than the integrity of the RF output signal 602 (FIG. 21) aslong as the RF output signal 602 has low frequency components for safepatient levels so as to avoid neuro-muscular stimulation. In anotherform, the frequency of an RF waveform can be changed on a continuousbasis in order to manage the peaks of the waveform. Waveform control isimportant as more complex RF waveforms, such as a coagulation-typewaveform 642, as illustrated in the graph 640 shown in FIG. 25, areimplemented with the system. Again, time (t) is shown along thehorizontal axis and voltage (V) is shown along the vertical axis. Thecoagulation-type waveform 642 illustrated in FIG. 25 has a crest factorof 5.8, for example.

While the examples herein are described mainly in the context ofelectrosurgical instruments, it should be understood that the teachingsherein may be readily applied to a variety of other types of medicalinstruments. By way of example only, the teachings herein may be readilyapplied to tissue graspers, tissue retrieval pouch deployinginstruments, surgical staplers, ultrasonic surgical instruments, etc. Itshould also be understood that the teachings herein may be readilyapplied to any of the instruments described in any of the referencescited herein, such that the teachings herein may be readily combinedwith the teachings of any of the references cited herein in numerousways. Other types of instruments into which the teachings herein may beincorporated will be apparent to those of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Various aspects of the disclosed surgical instruments have applicationin conventional endoscopic and open surgical instrumentation as well asapplication in robotic-assisted surgery. For instance, those of ordinaryskill in the art will recognize that various teaching herein may bereadily combined with various teachings of U.S. Pat. No. 6,783,524,titled ROBOTIC SURGICAL TOOL WITH ULTRASOUND CAUTERIZING AND CUTTINGINSTRUMENT, published Aug. 31, 2004, the disclosure of which isincorporated by reference herein.

Aspects of the devices disclosed herein can be designed to be disposedof after a single use, or they can be designed to be used multipletimes. Aspects may be, in either or both cases, reconditioned for reuseafter at least one use. Reconditioning may include any combination ofthe steps of disassembly of the device, followed by cleaning orreplacement of particular pieces, and subsequent reassembly. Inparticular, aspects of the device may be disassembled, and any number ofthe particular pieces or parts of the device may be selectively replacedor removed in any combination. Upon cleaning and/or replacement ofparticular parts, aspects of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a surgicalteam immediately prior to a surgical procedure. Those skilled in the artwill appreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, aspects described herein may be processed beforesurgery. First, a new or used instrument may be obtained and ifnecessary cleaned. The instrument may then be sterilized. In onesterilization technique, the instrument is placed in a closed and sealedcontainer, such as a plastic or TYVEK bag. The container and instrumentmay then be placed in a field of radiation that can penetrate thecontainer, such as gamma radiation, x-rays, or high-energy electrons.The radiation may kill bacteria on the instrument and in the container.The sterilized instrument may then be stored in the sterile container.The sealed container may keep the instrument sterile until it is openedin a medical facility. A device may also be sterilized using any othertechnique known in the art, including but not limited to beta or gammaradiation, ethylene oxide, or steam.

Having shown and described various aspects of surgical instruments andgenerators therefor disclosed herein, further adaptations of the methodsand systems described herein may be accomplished by appropriatemodifications by one of ordinary skill in the art without departing fromthe scope of the present disclosure. Several of such potentialmodifications have been mentioned, and others will be apparent to thoseskilled in the art. For instance, the examples, aspects, geometrics,materials, dimensions, ratios, steps, and the like discussed above areillustrative and are not required. Accordingly, the scope of the presentdisclosure should be considered in terms of the following claims and isunderstood not to be limited to the details of structure and operationshown and described in the specification and drawings.

While various details have been set forth in the foregoing description,it will be appreciated that the various aspects of the presentdisclosure may be practiced without these specific details. For example,for conciseness and clarity selected aspects have been shown in blockdiagram form rather than in detail. Some portions of the detaileddescriptions provided herein may be presented in terms of instructionsthat operate on data that is stored in a computer memory. Suchdescriptions and representations are used by those skilled in the art todescribe and convey the substance of their work to others skilled in theart. In general, an algorithm refers to a self-consistent sequence ofsteps leading to a desired result, where a “step” refers to amanipulation of physical quantities which may, though need notnecessarily, take the form of electrical or magnetic signals capable ofbeing stored, transferred, combined, compared, and otherwisemanipulated. It is common usage to refer to these signals as bits,values, elements, symbols, characters, terms, numbers, or the like.These and similar terms may be associated with the appropriate physicalquantities and are merely convenient labels applied to these quantities.

Unless specifically stated otherwise as apparent from the foregoingdiscussion, it is appreciated that, throughout the foregoingdescription, discussions using terms such as “processing” or “computing”or “calculating” or “determining” or “displaying” or the like, refer tothe action and processes of a computer system, or similar electroniccomputing device, that manipulates and transforms data represented asphysical (electronic) quantities within the computer system's registersand memories into other data similarly represented as physicalquantities within the computer system memories or registers or othersuch information storage, transmission or display devices.

It is worthy to note that any reference to “one aspect” or “an aspect”means that a particular feature, structure, or characteristic describedin connection with the aspect is included in at least one aspect. Thus,appearances of the phrases “in one aspect” or “in an aspect” in variousplaces throughout the specification are not necessarily all referring tothe same aspect. Furthermore, the particular features, structures orcharacteristics may be combined in any suitable manner in one or moreaspects.

Although various aspects have been described herein, many modifications,variations, substitutions, changes, and equivalents to those aspects maybe implemented and will occur to those skilled in the art. Also, wherematerials are disclosed for certain components, other materials may beused. It is therefore to be understood that the foregoing descriptionand the appended claims are intended to cover all such modifications andvariations as falling within the scope of the disclosed aspects. Thefollowing claims are intended to cover all such modification andvariations.

Some or all of the aspects described herein may generally comprisetechnologies for managing RF and ultrasonic signals output by agenerator, or otherwise according to technologies described herein. In ageneral sense, those skilled in the art will recognize that the variousaspects described herein which can be implemented, individually and/orcollectively, by a wide range of hardware, software, firmware, or anycombination thereof can be viewed as being composed of various types of“electrical circuitry.” Consequently, as used herein “electricalcircuitry” includes, but is not limited to, electrical circuitry havingat least one discrete electrical circuit, electrical circuitry having atleast one integrated circuit, electrical circuitry having at least oneapplication specific integrated circuit, electrical circuitry forming ageneral purpose computing device configured by a computer program (e.g.,a general purpose computer configured by a computer program which atleast partially carries out processes and/or devices described herein,or a microprocessor configured by a computer program which at leastpartially carries out processes and/or devices described herein),electrical circuitry forming a memory device (e.g., forms of randomaccess memory), and/or electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, or optical-electricalequipment). Those having skill in the art will recognize that thesubject matter described herein may be implemented in an analog ordigital fashion or some combination thereof.

The foregoing detailed description has set forth various aspects of thedevices and/or processes via the use of block diagrams, flowcharts,and/or examples. Insofar as such block diagrams, flowcharts, and/orexamples contain one or more functions and/or operations, it will beunderstood by those within the art that each function and/or operationwithin such block diagrams, flowcharts, or examples can be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or virtually any combination thereof. In one aspect, severalportions of the subject matter described herein may be implemented viaApplication Specific Integrated Circuits (ASICs), Field ProgrammableGate Arrays (FPGAs), digital signal processors (DSPs), or otherintegrated formats. Those skilled in the art will recognize, however,that some aspects disclosed herein, in whole or in part, can beequivalently implemented in integrated circuits, as one or more computerprograms running on one or more computers (e.g., as one or more programsrunning on one or more computer systems), as one or more programsrunning on one or more processors (e.g., as one or more programs runningon one or more microprocessors), as firmware, or as virtually anycombination thereof, and that designing the circuitry and/or writing thecode for the software and or firmware would be well within the skill ofone of skill in the art in light of this disclosure. In addition, thoseskilled in the art will appreciate that the mechanisms of the subjectmatter described herein are capable of being distributed as a programproduct in a variety of forms, and that an illustrative aspect of thesubject matter described herein applies regardless of the particulartype of signal bearing medium used to actually carry out thedistribution. Examples of a signal bearing medium include, but are notlimited to, the following: a recordable type medium such as a floppydisk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk(DVD), a digital tape, a computer memory, etc.; and a transmission typemedium such as a digital and/or an analog communication medium (e.g., afiber optic cable, a waveguide, a wired communications link, a wirelesscommunication link (e.g., transmitter, receiver, transmission logic,reception logic, etc.), etc.).

All of the above-mentioned U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications, non-patent publications referred to in this specificationand/or listed in any Application Data Sheet, or any other disclosurematerial are incorporated herein by reference, to the extent notinconsistent herewith. As such, and to the extent necessary, thedisclosure as explicitly set forth herein supersedes any conflictingmaterial incorporated herein by reference. Any material, or portionthereof, that is said to be incorporated by reference herein, but whichconflicts with existing definitions, statements, or other disclosurematerial set forth herein will only be incorporated to the extent thatno conflict arises between that incorporated material and the existingdisclosure material.

One skilled in the art will recognize that the herein describedcomponents (e.g., operations), devices, objects, and the discussionaccompanying them are used as examples for the sake of conceptualclarity and that various configuration modifications are contemplated.Consequently, as used herein, the specific exemplars set forth and theaccompanying discussion are intended to be representative of their moregeneral classes. In general, use of any specific exemplar is intended tobe representative of its class, and the non-inclusion of specificcomponents (e.g., operations), devices, and objects should not be takenlimiting.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations are not expressly set forth herein for sakeof clarity.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely exemplary, and that in fact many other architectures may beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality can be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable,” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents, and/or wirelessly interactable, and/or wirelesslyinteracting components, and/or logically interacting, and/or logicallyinteractable components.

Some aspects may be described using the expression “coupled” and“connected” along with their derivatives. It should be understood thatthese terms are not intended as synonyms for each other. For example,some aspects may be described using the term “connected” to indicatethat two or more elements are in direct physical or electrical contactwith each other. In another example, some aspects may be described usingthe term “coupled” to indicate that two or more elements are in directphysical or electrical contact. The term “coupled,” however, also maymean that two or more elements are not in direct contact with eachother, but yet still co-operate or interact with each other.

In some instances, one or more components may be referred to herein as“configured to,” “configurable to,” “operable/operative to,”“adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Thoseskilled in the art will recognize that “configured to” can generallyencompass active-state components and/or inactive-state componentsand/or standby-state components, unless context requires otherwise.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from the subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true spirit and scope of the subject matter described herein.It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to claims containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations.

In addition, even if a specific number of an introduced claim recitationis explicitly recited, those skilled in the art will recognize that suchrecitation should typically be interpreted to mean at least the recitednumber (e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that typically a disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms unless context dictates otherwise. For example, the phrase “Aor B” will be typically understood to include the possibilities of “A”or “B” or “A and B.”

With respect to the appended claims, those skilled in the art willappreciate that recited operations therein may generally be performed inany order. Also, although various operational flows are presented in asequence(s), it should be understood that the various operations may beperformed in other orders than those which are illustrated, or may beperformed concurrently. Examples of such alternate orderings may includeoverlapping, interleaved, interrupted, reordered, incremental,preparatory, supplemental, simultaneous, reverse, or other variantorderings, unless context dictates otherwise. Furthermore, terms like“responsive to,” “related to,” or other past-tense adjectives aregenerally not intended to exclude such variants, unless context dictatesotherwise.

In certain cases, use of a system or method may occur in a territoryeven if components are located outside the territory. For example, in adistributed computing context, use of a distributed computing system mayoccur in a territory even though parts of the system may be locatedoutside of the territory (e.g., relay, server, processor, signal-bearingmedium, transmitting computer, receiving computer, etc. located outsidethe territory).

A sale of a system or method may likewise occur in a territory even ifcomponents of the system or method are located and/or used outside theterritory. Further, implementation of at least part of a system forperforming a method in one territory does not preclude use of the systemin another territory.

Although various aspects have been described herein, many modifications,variations, substitutions, changes, and equivalents to those aspects maybe implemented and will occur to those skilled in the art. Also, wherematerials are disclosed for certain components, other materials may beused. It is therefore to be understood that the foregoing descriptionand the appended claims are intended to cover all such modifications andvariations as falling within the scope of the disclosed aspects. Thefollowing claims are intended to cover all such modification andvariations.

In summary, numerous benefits have been described which result fromemploying the concepts described herein. The foregoing description ofthe one or more aspects has been presented for purposes of illustrationand description. It is not intended to be exhaustive or limiting to theprecise form disclosed. Modifications or variations are possible inlight of the above teachings. The one or more aspects were chosen anddescribed in order to illustrate principles and practical application tothereby enable one of ordinary skill in the art to utilize the variousaspects and with various modifications as are suited to the particularuse contemplated. It is intended that the claims submitted herewithdefine the overall scope.

Various aspects of the subject matter described herein are set out inthe following numbered clauses:

1. A system for managing radio frequency (RF) and ultrasonic signalsoutput by a generator, comprising: a surgical instrument comprising anRF energy output, an ultrasonic energy output, and a circuit configuredto receive a combined RF and ultrasonic signal from the generator;wherein the circuit is configured to filter frequency content of thecombined RF and ultrasonic signal and is configured to provide a firstfiltered signal to the RF energy output and a second filtered signal tothe ultrasonic energy output.

2. The system of clause 1, wherein the circuit comprises a resonator.

3. The system of clause 1 or 2, wherein the circuit comprises a highfrequency band-stop filter.

4. The system of any one of clauses 1-3, wherein the high frequencyband-stop filter comprises a first LC filter circuit and a second LCfilter circuit.

5. The system of any one of clauses 1-4, wherein the combined RF andultrasonic signal comprises a 350 kHz component.

6. The system of any one of clauses 1-5, wherein the combined RF andultrasonic signal comprises a 55 kHz component.

7. The system of any one of clauses 1-6, wherein the surgical instrumentis configured to apply a therapy from the RF energy output and theultrasonic energy output simultaneously.

8. A system for managing radio frequency (RF) and ultrasonic signalsoutput by a generator, comprising: a surgical instrument comprising anRF energy output, an ultrasonic energy output, and a circuit configuredto receive a combined RF and ultrasonic signal from the generator;wherein the circuit is configured to switch between the RF energy outputand the ultrasonic energy output according to the combined RF andultrasonic signal received from the generator.

9. The system of clause 8, wherein the circuit comprises two pairs ofMOSFET switches.

10. The system of clause 9, wherein each of the two pairs of MOSFETswitches is connected source to source.

11. The system of clause 9 or 10, further comprising a first coupledinductor and a second coupled inductor.

12. The system of clause 11, wherein the gate of each MOSFET of a firstpair of MOSFET switches is coupled together and is coupled to the firstcoupled inductor.

13. The system of clause 11 or 12, wherein the gate of each MOSFET of asecond pair of MOSFET switches is coupled together and is coupled to thesecond coupled inductor.

14. The system of any one of clauses 11-13, further comprising a firstcapacitor and a second capacitor, wherein the first capacitor is coupledto the primary side of the first coupled inductor and the secondcapacitor is coupled to the primary side of the second coupled inductor.

15. The system of any one of clauses 9-14, further comprising an ASIC, afirst pulse transformer, and a second pulse transformer, wherein theASIC is coupled to the first and second pulse transformers, and whereinthe first pulse transformer is coupled to a first pair of the two pairsof MOSFET switches and the second pulse transformer is coupled to asecond pair of the two pairs of MOSFET switches.

16. The system of clause 15, wherein each of the two pairs of MOSFETswitches are connected source to source.

17. The system of clause 16, wherein the gate of each MOSFET of thefirst pair of MOSFET switches is coupled together and is coupled to thefirst pulse transformer.

18. The system of clause 16 or 17, wherein the gate of each MOSFET of asecond pair of MOSFET switches is coupled together and is coupled to thesecond pulse transformer.

19. The system of clause 18, wherein the circuit comprises a firstswitching element coupled to the RF energy output and a second switchingelement coupled to the ultrasonic energy output.

20. The system of clause 19, wherein the first switching element and thesecond switching element are each electromechanical relays.

21. The system of clause 19 or 20, wherein the first switching elementand the second switching element are coupled to an ASIC.

22. The system of any one of clauses 19-21, further comprising a switchmechanism to actuate the first switching element and the secondswitching element.

23. The system of clause 22, wherein the switch mechanism is amechanical rocker style switch mechanism.

24. A system for managing radio frequency (RF) and ultrasonic signalsoutput by a generator, comprising: a surgical instrument comprising anRF energy output, an ultrasonic energy output, and a circuit configuredto receive a combined RF and ultrasonic signal from the generator;wherein the circuit comprises: a filter circuit configured to filterfrequency content of the combined signal; and a switching elementconfigured to switch between an on-state and an off-state to one of theRF energy output or the ultrasonic energy output according to thecombined RF and ultrasonic signal received from the generator.

25. The system of clause 24, wherein the filter circuit is coupled tothe ultrasonic energy output and the switching element is coupled to theRF energy output.

26. A system for managing radio frequency (RF) and ultrasonic signalsoutput by a generator, comprising: a surgical instrument comprising adirect current (DC) motor load, an ultrasonic energy output, and acircuit; wherein the circuit is configured to: receive a combined RF andultrasonic signal from the generator; generate an ultrasonic filteredsignal by filtering ultrasonic frequency content from the combined RFand ultrasonic signal; generate DC voltage by filtering RF frequencycontent from the combined RF and ultrasonic signal; provide the DCvoltage to the DC motor load; and provide the ultrasonic filtered signalto the ultrasonic energy output.

27. The system of clause 26, wherein the surgical instrument furthercomprises at least one electrical component, and the DC motor load isconfigured to power the at least one electrical component using thegenerated DC voltage.

28. The system of clause 26 or 27, wherein the at least one electricalcomponent comprises an end effector.

29. The system of any one of clauses 26-28, wherein the at least oneelectrical component comprises one or more light emitting diodes (LEDs).

30. The system of any one of clauses 26-29, wherein the at least oneelectrical component comprises one or more sensors configured to detecta physiological condition of tissue at a surgical site.

31. The system of any of clauses 26-30, wherein the circuit comprises ahigh frequency band-stop filter.

32. The system of any one of clauses 26-31, wherein filtering theultrasonic frequency content comprises filtering the ultrasonicfrequency content through the high frequency band-stop filter.

33. The system of any one of clauses 26-32, wherein generating the DCvoltage by filtering comprises filtering the RF frequency contentthrough the high frequency band-stop filter.

34. The system of any one of clauses 26-33, wherein the circuitcomprises a rectifier configured to produce the DC voltage.

35. The system of any one of clauses 26-34, wherein the surgicalinstrument is configured to apply a therapy of RF energy through the DCmotor load and the ultrasonic energy output simultaneously.

36. The system of any one of clauses 26-35, wherein the surgicalinstrument is configured to switch between applying RF energy throughthe DC motor load and applying ultrasonic energy through the ultrasonicenergy output.

37. The system of any one of clauses 26-36, wherein the circuit furthercomprises: an application specific integrated circuit (ASIC); a memorycoupled to the ASIC; a switch array coupled to the ASIC; and a rectifiercoupled to the ASIC; wherein the ASIC is configured to control switchingbetween the DC motor load and the ultrasonic energy output through theswitch array.

38. A surgical instrument comprising: a direct current (DC) motor load;an ultrasonic energy output, and a circuit; wherein the circuit isconfigured to: receive a combined radio frequency (RF) and ultrasonicsignal from a generator electrically coupled to the surgical instrument;generate an ultrasonic filtered signal by filtering ultrasonic frequencycontent from the combined RF and ultrasonic signal; generate DC voltageby filtering RF frequency content from the combined RF and ultrasonicsignal; provide the DC voltage to the DC motor load; and provide theultrasonic filtered signal to the ultrasonic energy output.

39. The surgical instrument of clause 38, further comprising an endeffector, and wherein the DC motor load is configured to power the endeffector using the generated DC voltage.

40. The surgical instrument of clause 38 or 39, wherein the circuitcomprises a high frequency band-stop filter.

41. The surgical instrument of any one of clauses 38-40, whereinfiltering the ultrasonic frequency content comprises filtering theultrasonic frequency content through the high frequency band-stopfilter.

42. The surgical instrument of any one of clauses 38-41, whereingenerating the DC voltage by filtering comprises filtering the RFfrequency content through the high frequency band-stop filter.

43. The surgical instrument of any one of clauses 38-42, wherein thesurgical instrument is configured to apply a therapy of RF energythrough the DC motor load and the ultrasonic energy outputsimultaneously.

44. The surgical instrument of any one of clauses 38-43, wherein thecircuit is further configured to switch between applying RF energythrough the DC motor load and applying ultrasonic energy through theultrasonic energy output.

45. A surgical instrument comprising: a direct current (DC) motor load;an ultrasonic energy output; and a circuit, the circuit comprising: anapplication specific integrated circuit (ASIC); a memory coupled to theASIC; a switch array coupled to the ASIC; and a rectifier coupled to theASIC; wherein the circuit is configured to: receive a combined radiofrequency (RF) and ultrasonic signal from a generator electricallycoupled to the surgical instrument; generate an ultrasonic filteredsignal by filtering ultrasonic frequency content from the combined RFand ultrasonic signal; generate DC voltage by filtering RF frequencycontent from the combined RF and ultrasonic signal; provide the DCvoltage to the DC motor load; and provide the ultrasonic filtered signalto the ultrasonic energy output; wherein the ASIC is configured tocontrol switching between applying RF energy through the DC motor loadand applying ultrasonic energy through the ultrasonic energy output.

1. A system for managing radio frequency (RF) and ultrasonic signalsoutput by a generator, comprising: a surgical instrument comprising adirect current (DC) motor load, an ultrasonic energy output, and acircuit; wherein the circuit is configured to: receive a combined RF andultrasonic signal from the generator; generate an ultrasonic filteredsignal by filtering ultrasonic frequency content from the combined RFand ultrasonic signal; generate DC voltage by filtering RF frequencycontent from the combined RF and ultrasonic signal; provide the DCvoltage to the DC motor load; and provide the ultrasonic filtered signalto the ultrasonic energy output.
 2. The system of claim 1, wherein thesurgical instrument further comprises at least one electrical component,and the DC motor load is configured to power the at least one electricalcomponent using the generated DC voltage.
 3. The system of claim 2,wherein the at least one electrical component comprises an end effector.4. The system of claim 2, wherein the at least one electrical componentcomprises one or more light emitting diodes (LEDs).
 5. The system ofclaim 2, wherein the at least one electrical component comprises one ormore sensors configured to detect a physiological condition of tissue ata surgical site.
 6. The system of claim 1, wherein the circuit comprisesa high frequency band-stop filter.
 7. The system of claim 6, whereinfiltering the ultrasonic frequency content comprises filtering theultrasonic frequency content through the high frequency band-stopfilter.
 8. The system of claim 6, wherein generating the DC voltage byfiltering comprises filtering the RF frequency content through the highfrequency band-stop filter.
 9. The system of claim 1, wherein thecircuit comprises a rectifier configured to produce the DC voltage. 10.The system of claim 1, wherein the surgical instrument is configured toapply a therapy of RF energy through the DC motor load and theultrasonic energy output simultaneously.
 11. The system of claim 1,wherein the surgical instrument is configured to switch between applyingRF energy through the DC motor load and applying ultrasonic energythrough the ultrasonic energy output.
 12. The system of claim 11,wherein the circuit further comprises: an application specificintegrated circuit (ASIC); a memory coupled to the ASIC; a switch arraycoupled to the ASIC; and a rectifier coupled to the ASIC; wherein theASIC is configured to control switching between the DC motor load andthe ultrasonic energy output through the switch array.
 13. A surgicalinstrument comprising: a direct current (DC) motor load; an ultrasonicenergy output, and a circuit; wherein the circuit is configured to:receive a combined RF and ultrasonic signal from a generatorelectrically coupled to the surgical instrument; generate an ultrasonicfiltered signal by filtering ultrasonic frequency content from thecombined RF and ultrasonic signal; generate DC voltage by filtering RFfrequency content from the combined signal; provide the DC voltage tothe DC motor load; and provide the ultrasonic filtered signal to theultrasonic energy output.
 14. The surgical instrument of claim 13,further comprising an end effector, and wherein the DC motor load isconfigured to power the end effector using the generated DC voltage. 15.The surgical instrument of claim 13, wherein the circuit comprises ahigh frequency band-stop filter.
 16. The surgical instrument of claim15, wherein filtering the ultrasonic frequency content comprisesfiltering the ultrasonic frequency content through the high frequencyband-stop filter.
 17. The surgical instrument of claim 15, whereingenerating the DC voltage by filtering comprises filtering the RFfrequency content through the high frequency band-stop filter.
 18. Thesurgical instrument of claim 13, wherein the surgical instrument isconfigured to apply a therapy of RF energy through the DC motor load andthe ultrasonic energy output simultaneously.
 19. The surgical instrumentof claim 13, wherein the circuit is further configured to switch betweenapplying RF energy through the DC motor load and applying ultrasonicenergy through the ultrasonic energy output.
 20. A surgical instrumentcomprising: a direct current (DC) motor load; an ultrasonic energyoutput; and a circuit, the circuit comprising: an application specificintegrated circuit (ASIC); a memory coupled to the ASIC; a switch arraycoupled to the ASIC; and a rectifier coupled to the ASIC; wherein thecircuit is configured to: receive a combined RF and ultrasonic signalfrom a generator electrically coupled to the surgical instrument;generate an ultrasonic filtered signal by filtering ultrasonic frequencycontent from the combined signal; generate DC voltage by filtering RFfrequency content from the combined signal; provide the DC voltage tothe DC motor load; and provide the ultrasonic filtered signal to theultrasonic energy output; wherein the ASIC is configured to controlswitching between applying RF energy through the DC motor load andapplying ultrasonic energy through the ultrasonic energy output.